THE PARENTING INSTINCT AND CHILDCARE IN THE HOMO SAPIENS AS SEEN IN MOST COMMUNITIES
Dr Jideofo
Kenechukwu Danmbaezue
Instinct, in zoology and psychology, is the innate
programming characteristic of a particular animal species that organises
complex patterns of behaviour, enabling members of a species to respond
appropriately to a wide range of situations in the natural world. Such
behaviours are usually involved patterns of responses to particular stimuli and
are often permanent patterns of feeding, mating, parenting, and expression of
aggression. In each species, these characteristic behaviour patterns are
developed and refined by the forces of natural selection in the process of
evolution.
Some
scholars make careful distinctions between learned behaviours and instinctive
behaviours. In recent years, however, researchers have generally agreed that
such distinctions are not particularly useful and that learning and instinct
interact to direct an animal’s behaviour in appropriate ways. Instinctive
behaviours are inherited from parents and are vitally important in helping an
animal adapt to and survive in any and every ecological environment it finds
itself. Thus, an animal transferred from one zoo to another in a different
climate learns to adjust like others that were there before its arrival and so
still lives a normal life!
Instinctive
behaviours can be extremely complex even in relatively simple animals, for
example, the remarkable navigational and communication skills possessed by
honey bees. A worker bee may fly a quarter of a mile or more from the hive in
search of flowers that are a good source of food. The sun usually serves as an
indicator of direction, but the bee can navigate accurately, even in a moderate
breeze, when a cloud hides the sun.
When it
finds a good source of food, the bee has the capacity to calculate a true
course back to the hive, allowing for wind and for apparent movement of the
sun. Upon returning to the hive, it communicates the location of the food
through a “dance” that conveys information about distance and direction. Other
bees use this information to go directly to the food. In this example, learning
and genetically coded patterns of behaviour each play an important role.
Instincts permit an animal to show highly adaptive and often very complex
behaviours without the necessity of learning those responses through trial and
error.
The role
that instinct plays in human behaviour is not yet clear. Some researchers feel
that human behaviours such as aggression and territoriality may have
instinctive components. Others feel that such a conclusion is not warranted by
the available data and that human behaviour is qualitatively different from
that of other animals. There is some danger of over generalising to human
behaviour from animal research; however, many of the same forces that direct
the behaviour of other animals are likely to influence human behaviour.
The term
instinct can also be applied to several constructs developed by Sigmund Freud
and other personality theorists (see Psychoanalysis). Freud theorized
that there are instincts for life and for death, and that the sexual drive is
essentially instinctive. This specific application of the term instinct
is unrelated to the way in which behavioural scientists use the term.
The Stock
Market/Rob Lewine
A Couple
without Children
Many couples remain
childless by choice or due to biological problems. Often they do not want
children to disrupt their lovemaking! They marry for companionship! Childless
families make up an increasing number of households in developed countries like
France and the United States.
Microsoft ® Encarta ®
Encyclopaedia 2004. © 1993-2003
PARENT AND CHILDCARE
Parent
and Child is a branch of the law of
domestic relations that determines the legal rights and obligations of fathers
or mothers to their children and of children to their parents. The legal
relationship is distinguished from the natural relationship; for example, two
persons may have a legal relationship of parent and child although there is no
natural relationship, as in the case of an adopted child.
In common law, in the United Kingdom United States
MODERN LAW
The legal relationships
of parent and child established under common law have been modified by statute
in Britain and the U.S. In general, such statutes provide that a married woman
is a joint guardian of her children with her husband, with equal powers,
rights, and duties. Either parent has the right to custody of the children of
the marriage, and in a divorce or separation, the court can award custody to
the parent best qualified and able to care for the children. Parents must
provide for their children such necessities of life as food, clothing, shelter,
education, and medical care; if they cannot or will not, state laws authorize
intervention by designated authorities to ensure that children's needs are met.
Children
who are physically or emotionally abused by their parents may be the subjects
of legal action in order to protect the children. Parents' rights to custody of
their children may be limited or, in extreme cases, terminated because of
failure to provide adequate care. Laws require a father to support his minor
children if he is able to do so, whether or not he has ever been married to
their mother. Failure to provide support may result in civil or criminal
proceedings against him. If paternity has been admitted or established, laws
permit children to inherit from their father's estate unless specifically
excluded in his will.
SURROGACY
Surrogate motherhood has become one
of the most difficult problems in modern family law. The term surrogate
mother was first used in connection with in vitro fertilization (see Infertility)
in the late 1970s. The newest use refers to the introduction, by artificial
insemination, of the sperm of a man whose wife is infertile into a woman who
has agreed, often by contract, to bear the child conceived because of the
insemination and then relinquish it to the couple after birth.
One argument against surrogacy
is that it is little more than formalized baby selling. The counter-argument is
that surrogacy is not baby selling because the husband of the couple receiving
the child is that child's biological father. Many state legislatures are
considering bills that would either make surrogate parenting entirely illegal
or strictly regulate it, for example, limiting or prohibiting the payment of
fees to the surrogate or to intermediaries. Most would require psychological
counselling for the prospective surrogate mother, legal representation for all
parties, and court approval of the contract.
CURRENT
ABERRATIONS IN PARENTHOOD
There has been
a desecration of family values over the centuries, so that today we have un-wed
mothers and unfit parents being tolerated in some permissive societies. This is
an irresponsible aspect of parenthood. Join in the crusade for campaigning
against it. However, since it has become a recurring decimal even in urban
cities of Africa, one cannot avoid treating its demerits, in the least, and
condemning the immaturity of those who fall prey to such unplanned families
that are very disadvantageous to raising good children.
Photo
Researchers, Inc./Vanessa Vick
Lesbian Couple
and Child
In recent years, gay and
lesbian couples have become visible participants in traditional family
pursuits. This lesbian couple is raising a son together. This has not reached Africa for now, and when it does,
it will be regarded as an anathema.
One such aberration is
lesbian couples adopting children and raising up such unfortunate children in
the absence of parents of both sexes. Of course, such kids will definitely have
deformed personality traits and socially, their peers will discriminate against
them! They will forever live with the scorn of the community! They may grow up
and hate their lesbian ‘parents’ since they were fake ones!
Tony Stone Images/Dan Bosler
Single-Parent Family
In a single-parent family, children live with
an unmarried, divorced, or widowed mother or father. In the United States Biafra and most other African countries. In all Africa , offspring of such families are regarded as
‘bastards’ a.k.a. social outcasts. Microsoft
®
Encarta ® Encyclopaedia 2004. © 1993-2003
Another
similar and in fact the most common aberration is the unwed mother, which is
directly the consequence of indiscipline among the youth. Such indiscriminate
indulgence in pre-marital sex is an aberration that results in single parenthood, and unfortunately, it is the
children that suffer emotionally as their personality will definitely be
deformed. Join this team of Happy Family Network crusaders to nip in the bud
the laxity in morality that is the remote cause of such aberrations in family
life!
If
present day parents shirk their responsibilities of being the primary educators
of their offspring in matters of morality and social ethics, then we shall have
failed in one of the very fundamental duties of responsible parenthood. What
legacy will such parents leave for their posterity? Will they be happy to have
all their sons and daughters become fathers and mothers without courtship,
engagement and formal marriage? We cannot fold our hands and pretend that there
is nothing we can do about it!
Contributed
By: Robert A. Jensen & Kenez J. Danmbaezue
CHAPTER FOUR
THE SOCIOANTHROPOLOGICAL STUDY OF FAMILIES
AN OVERVIEW
Family
as in the science of sociology and
anthropology is the basic unit of any social group of humans united
through bonds of kinship or marriage, which is present in all societies.
Ideally, the family provides its members with protection, companionship,
security and socialisation. The structure of the family and the needs that the
family fulfils vary from society to society. The nuclear family—two adults and
their children—is the main unit in some societies. In others, it is a
subordinate part of an extended family, which also consists of grandparents and
other relatives. A third family unit is the single-parent family, in which
children live with an unmarried, divorced, or widowed mother or father.
Anthropologists and social
scientists have developed several theories about how family structures and
functions evolved. In prehistoric hunting and gathering societies, two or three
nuclear families, usually linked through bonds of kinship, banded together for
part of the year but dispersed into separate nuclear units in those seasons
when food was scarce. The family was an economic unit; men hunted, while women
gathered and prepared food and tended children. Infanticide and expulsion of
the infirm that could not work were common. Some anthropologists contend that
prehistoric people were monogamous, because monogamy prevails in
non-industrial, tribal forms of contemporary society.
Social scientists believe
that the modern Western family developed largely from that of the ancient
Hebrews, whose families were patriarchal in structure. The family resulting
from the Greco-Roman culture was also patriarchal and bound by strict religious
precepts. In later centuries, as the Greek and then the Roman civilizations
declined, so did their well-ordered family life.
With the advent of Christianity,
marriage and childbearing became central concerns in religious teaching. The
purely religious nature of family ties was partly abandoned in favour of civil
bonds after the Reformation, which began in the 1500s. Most Western nations now
recognize the family relationship as primarily a civil matter.
THE MODERN
FAMILY
Historical studies have
shown that family structure has been less changed by urbanization and
industrialization than was once supposed. The nuclear family was the most
prevalent pre-industrial unit and is still the basic unit of social
organization. The modern family differs from earlier traditional forms,
however, in its functions, composition, and life cycle and in the roles of husbands
and wives.
Globe Photos, Inc.
Family Stereotypes
During the 1950s, several American television-shows portrayed an
idealized middle-class family consisting of a wise breadwinner father, a
cheerful and attractive wife, and socially and academically successful
children. American actor Robert Young, who starred as Jim Anderson in the
series “Father Knows Best,” epitomised the role of all knowing, morally superior
husband and father. Here, Anderson
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Encyclopaedia 2004. © 1993-2003
The only function of the
family that continues to survive all change is the provision of affection and
emotional support by and to all its members, particularly infants and young
children. Specialized institutions now perform many of the other functions that
were once performed by the agrarian family: economic production, education,
religion, and recreation. Jobs are usually separate from the family group;
family members often work in different occupations and in locations away from
the home. Education is provided by the state or by private groups. Religious
training and recreational activities are available outside the home, although
both still have a place in family life. The family is still responsible for the
socialization of children. Even in this capacity, however, the influence of
peers and of the mass media has assumed a larger role.
Family composition in
industrial societies has changed dramatically. The average number of children
born to a woman in the United States
Some of these developments
are related to ongoing changes in women’s roles. Women in all stages of family
life have joined the labor force. Rising expectations of personal gratification
through marriage and family, together with eased legal grounds for divorce and
increasing employment opportunities for women, have contributed to a rise in
the divorce rate in the United States United States
During the 20th century,
extended family households declined in prevalence. This change is associated
particularly with increased residential mobility and with diminished financial
responsibility of children for aging parents, as pensions from jobs and
government-sponsored benefits for retired people became more common.
By the 1970s, the prototypical
nuclear family had yielded somewhat to modified structures including the
one-parent family, the stepfamily, and the childless family. One-parent
families in the past were usually the result of the death of a spouse. Now,
however, most one-parent families are the result of divorce, although some are
created when unmarried mothers bear children. In 1991, more than one out of
four children lived with only one parent, usually the mother. Most one-parent
families, however, eventually became two-parent families through remarriage.
A stepfamily is created
by a new marriage of a single parent. It may consist of a parent and children
and a childless spouse, a parent and children and a spouse whose children live
elsewhere, or two joined one-parent families. In a stepfamily, problems in
relations between non-biological parents and children may generate tension; the
difficulties can be especially great in the marriage of single parents when the
children of both parents live with them as siblings.
Childless families may
be increasingly the result of deliberate choice and the availability of birth
control. For many years, the proportion of couples who were childless declined
steadily as venereal and other diseases that cause infertility were conquered.
In the 1970s, however, the changes in the status of women reversed this trend.
Couples often elect to have no children or to postpone having them until their
careers are well established.
Since the 1960s, several
variations on the family unit have emerged. More unmarried couples are living together,
before or instead of marrying. Some elderly couples, most often widowed, are
finding it more economically practical to cohabit without marrying. Homosexual
couples also live together as a family more openly today, sometimes sharing
their households with the children of one partner or with adopted or foster
children. Communal families, made up of groups of related or unrelated people,
have long existed in isolated instances (see Communal Living). Such
units began to occur in the United States
CURRENT
TRENDS
All industrial nations
are experiencing family trends similar to those found in the United States
Unchecked population growth
in developing nations threatens the family system. The number of surviving
children in a family has rapidly increased as infectious diseases, famine, and
other causes of child mortality have been reduced. Because families often
cannot support so many children, the reduction in infant mortality has posed a
challenge to the nuclear family and to the resources of developing nations.
As you may
have observed, there are variants in the value systems now attached to the
marriage institution in general and family life in particular. What used to be
sacred is no more held in high esteem! Who, in the Victorian age would imagine
that two women would live as husband and wife, knowing fully well that they
could never have children by themselves, they go ahead to adopt some else’s
child and rear as their own! Who would even consider allowing such unfit ‘parents’
adopt his/her child? There has been a lot of desecration of family values. We
at the NGO, HAPPY FAMILY NETWORK INTERNATIONAL are committed to reversing these
obnoxious trends! Please assist us by at least instructing your friends and
your children to see these aberrations for what they truly are. They are the
demonic attack on the sanctity of marriage and exemplary family lifestyles! If
we all undertake to educate adolescents near us, we can succeed. Don’t sit on
the fence. Join in the crusade!
Contributed By: Ida Harper Simpson & Kenez Jideofo Danmbaezue
A TYPICAL AFRICAN VIEW OF FAMILY LIFE
In the traditional African community, all the descendants of one great
ancestor live and cater for each other in the now famous “AFRICAN EXTENDED
FAMILY SYSTEM.” In this system, the concept of nuclear family is foreign as
everyone is everybody’s concern and everybody’s keeper. Democratic decisions
submit to patriarchal ones, as elders have the final say at a communal
meeting. “Custom, then, is the great
guide of human life,” wrote Scottish philosopher David Hume. Knowing the
customs of a country is, in effect, a guide to understanding the soul of that
country and its people. The following Sidebar is intended to provide a glimpse
into the unique world of this nation’s customs: how people marry, how families
celebrate holidays and other occasions, what people eat, how they socialize and
have fun.
MARRIAGE
AND FAMILY CUSTOMS OF DEMOCRATIC
REPUBLIC OF THE CONGO
Traditionally,
marriage is a family affair and is at least partly arranged by parents. Among
matrilineal families, the preferred marriage partner is a cousin—one of the
mother’s brothers’ children. However, that pattern is slowly changing,
especially in urban areas.
Although family structure
varies greatly among the different ethnic groups, much emphasis is placed on
group goals and overall family welfare. Large extended families are normal, and
they usually live under the same roof or in a tight group of homes. In the
western region of Democratic
Republic of the Congo
Funerals for family or close
friends are often elaborate events. Practices vary, but the family of the
deceased usually announces a period of mourning at a large gathering of family
and friends. These gatherings involve singing, dancing, speeches, and crying
into early morning hours. At the end of the designated period, typically 40
days, the mourning is lifted at a large, sometimes lavish celebration. Friends
and family attend this event to show their concern for the immediate family of
the deceased. These funerals also serve as an important means to maintain
personal, romantic, and professional contacts.
Panos
Pictures/Marcus Rose
Extended Family
In some societies, the extended family is the most
common unit of social organization. This Pakistani family consists of three
generations of relatives who live together.
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EATING
Staple foods include
cassava, rice, potatoes, bananas, yams, beans, maize, fish, groundnuts, and
various other fruits and vegetables. One of the most common foods is fufu, a
mealy paste made from flour and water. Known by a variety of names in different
parts of the country, fufu is typically served with a sauce made from tomatoes
or peanuts. Another popular food is shikwanga, a dish from the western
regions of Congo (DRC) that is made from manioc flour and water. Sauces are
served with most meals. Palm oil sauces are especially common, and most sauces
are prepared over a wood or charcoal fire, even in urban areas. Common fruits
include mangoes, oranges, papaws, and coconuts. Some types of food must be
purchased daily because people do not have ways to keep them fresh. As a
result, of years of political crisis and the breakdown of many services,
adequate supplies of food are failing to reach some areas.
Eating customs vary widely.
Silverware is very common in urban areas, but people often eat with their hands
in rural areas. People usually eat with the fingers of the right hand only. Men
and women sometimes dine separately, washing their hands in bowls of warm soapy
water at the end of the meal. Portions may be served individually or in a
communal bowl depending on local custom. When sharing a bowl, people eat only
from the part directly in front of them. Only the eldest distribute meat to
those eating the meal.
SOCIALISING
In urban areas, men and
women generally shake hands and smile when greeting. The French term Bonjour
(“Good day”) is used among many people in urban areas, but among Lingala
speakers, Mbote (“Hello”) is more common and is followed by Sango nini?
(“What’s new?”).
In rural areas, men do not
usually shake hands with women, but will with other men. Some rural women greet
men by clapping their hands a few times and bowing slightly. In some areas, men
greet each other by gently touching the side of the forehead—much like the
European custom of kissing cheeks—during a handshake. In the eastern and
south-eastern parts of the country, the Swahili greeting Jambo (“Hello”) is
common.
Other greetings vary
according to ethnic group. In virtually all parts of the country, greetings are
more elaborate and lively than goodbyes.
Visiting is important.
Family and close friends often drop by unannounced, but strangers are expected
to make arrangements in advance. People often socialize in outdoor courtyards
rather than inside homes. Socializing indoors is reserved for special events,
usually occasions when the guests are of a markedly higher social status than
the hosts. When a person first pays a visit, a gift is not appropriate. Guests
may give small gifts, such as food or an item for the house, after they
establish a relationship.
First-time visitors are
directed where to sit by the hosts, and the guests generally remain seated.
Good friends and members of the extended family have greater liberty to make
themselves at home. If children are present, they are expected to greet each
adult with a handshake and perhaps a kiss on the cheek. They are then usually
dismissed while the adults socialize.
If a host offers to share a
meal, the guest should first show reluctance to join the host’s table before
finally accepting the offer. It is important to try at least some of the food
as a gesture of goodwill. In Biafra, refusal to eat a morsel might be
misinterpreted as social status consciousness or pride!
RECREATION
Soccer is the most popular
sport in Congo (DRC). Rural inhabitants enjoy gathering to dance and play
drums. Many urban people spend their leisure time socializing, dancing, or
listening to local jazz.
HOLIDAYS AND CELEBRATIONS
- Public holidays include New Year’s Day
(1 January);
- The Commemoration of the Martyrs of
Independence (4 January);
- Easter; Labour Day (1 May);
- Promulgation of 1967 Constitution and
Day of the Fishermen (24 June);
- Independence Day (30 June);
- Parents’ Day (1 August); and
- Youth Day (14 October).
- Veterans Day is observed on 17 November
and
- Anniversary of the Second Republic on 24
November.
- Christmas Day is celebrated on 25
December.
Source: Encarta Interactive
World Atlas
Microsoft ® Encarta ® Encyclopaedia 2004. © 1993-2003
Microsoft Corporation. All rights reserved.
What has been described
above, with only minor alterations, can apply to most of the communities along
the West Coast of Africa. The Popular African Extended Family System takes
child rearing as everybody’s business. In Biafra, especially for the Igbo
ethnic group: “A Child is owned by the Community.” The initiation rites for
teenage boys and the rites of passage for the girls at menarche ensure the
inculcation of the norms and mores of the community. Every adult has an
obligation towards the child in danger as well as the erring child. Our people
say: “An adult does not stay at home and a pregnant goat delivers while still
tied up with a rope!” Again, we say: “One does not chase rats while one’s homestead
is on fire.”
In the traditional setting,
every child helps an elder carry his loads, stands up so that an older person
can have a seat, rune errands enthusiastically, and is polite even to
strangers! Unfortunately, this code is disappearing due to westernisation,
urbanisation and the anonymity associated with township life! The competing
religious groups and their discriminatory rules do not help matters! The
overwhelming influence of partisan politics, class-consciousness ethnocentric
stereotypes, fanatical religio-cultural attitudes and other forms of, social
prejudice is quite palpable. The arrival cellular phones, the Internet and
other mass media gadgets compound this hopeless state of degeneration of
values, once held sacrosanct by our traditional religion, norms and mores!
Dr & Mrs. Jideofo Kenechukwu Danmbaezue
Chief & Lolo Emmanuel Agha Mbey
&
Sir & Lady Andrew Okoliukwu Okeukwu
CHAPTER
FIVE
GENETIC COUNSELLING BEFORE WEDDING
Genetics
is the science of inheritance and a specialty in Zoology. In the medical field
its research results have been appropriated to predict health problems that
newly weds and their offspring might experience after they might signing on the
dotted lines. It is worth the while of every intending couple to avail
themselves of our services in this prophylactic approach to marital
counselling. You can forestall many headaches and heartaches by listening to
our advice. Do not place your children’s health in jeopardy!
Genetic Counselling is
the medical specialty that helps parents
and prospective parents evaluate and
cope with their risk of passing hereditary disorders to their children. Genetic counselling also helps individuals
assess the possibility that they will get a medical condition known or
suspected to have a genetic basis, such as Huntington’s disease, breast cancer,
or Alzheimer’s disease.
Photo
Researchers, Inc./Omikron/Science Source
Sickled Blood
Cell
The curved, crescent-shaped
blood cell (bottom, left)
signals the presence of sickle-cell anaemia, a genetic disorder that affects
about 72,000 people in the United States, primarily African Americans. It is
usually caused by a genetic mutation, thus this type of anaemia results from
abnormal haemoglobin, the oxygen-carrying component of red blood cells, which
distorts the shape of blood cells after they have released oxygen. The sickled
cells cannot pass smoothly through tiny blood vessels. The resulting blockages
cause intense pain to the sufferer, often in childhood, and serious
deficiencies of oxygen and other blood nutrients throughout the body. Most
carriers die before their twenty-first birthday
Hafani Organisation &
Microsoft ® Encarta ® Encyclopaedia 2004. © 1993-2003
In
developed countries, at least 1 infant in every 100 is born with a
disorder caused by an alteration in 1 or more of the estimated 50,000 human
genes. In third world countries, the figure is higher. Genes are segments of
deoxyribonucleic acid (DNA), the hereditary molecule found in the chromosomes
of cells. The severity of genetic disorders varies from mild conditions such as
colour blindness to serious diseases such as Duchenne muscular dystrophy and
Tay-Sachs disease. In most cases, a team of health experts at a medical centre
provides genetic counselling. The team typically consists of counsellors who
have graduate training in genetics, psychology, population statistics, and
medical education, along with physicians who have advanced training in human
genetics. The team also may include nurses, social workers, and psychologists
who have specialized skills in patient education and public health.
Genetic counselling may
involve more than one visit between a counsellor and a client, who may be an individual,
a couple, or an entire family. During the first visit, the counsellor gathers
information about the client’s family medical history. The counsellor may
discuss options for diagnostic tests that could help determine if a person is
at risk for passing an inherited disorder on to children or is susceptible to a
particular genetic disease.
After
considering these options, the client may choose to undergo testing at that
time or in a follow-up session. When testing is completed, the genetic
counsellor analyses the family history and test results to determine whether a
genetic disorder exists within a family and, if so, how it is inherited. The
good counsellor then discusses those conclusions with the client. Genetic
counsellors help the client cope with the emotional repercussions of the
diagnosis as well as any practical concerns. Genetic counsellors respect the
privacy of the individual and family, keeping all information exchanged during
counselling sessions confidential. Every parent-to-be who fails to do this is
irresponsible and not worthy of the appellation!
BENEFICIARIES OF
GENETICAL COUNSELLING
Many prospective parents use genetic counselling to help
resolve issues surrounding pregnancy and infertility. Genetic counselling is
helpful to parents who already have a
child with a genetic disorder so they can learn more about the condition and
the chance that their other children may be affected. People with a family
history of life-threatening diseases may consult a genetic counsellor to learn
the probability that they will develop a disease. Others seek genetic
counselling to determine the likelihood that they will develop a disease that
occurs more frequently in their ethnic group.
|
A
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Prospective Parents
|
A couple that is thinking
about conceiving a child may want to consider genetic counselling for several
reasons. For instance, many women aged 35 or older seek genetic counselling
because they are at a higher risk than younger women of giving birth to a child
with a chromosomal abnormality. These abnormalities occur when a child inherits
all or part of an extra copy of a chromosome. Down syndrome, the most common
chromosomal disorder, is almost nine times more common in babies born to women
aged 40 than those born to women aged 30. Couples who already have a child who
was born with a genetic disorder may seek genetic counselling to determine the
risk that future children may be similarly affected.
© Microsoft Corporation. All
Rights Reserved.
Recessive Gene
Transmission
Some genes that cause
genetic diseases interact in a dominant-recessive pattern. In these cases, two
copies of the recessive gene are required for the disease to occur. A person
who has just one copy of the recessive gene is termed a carrier, since he or she carries the gene but is not affected by
it. In the illustration above, the dominant gene is represented in green, and
the recessive in blue. For the couple on the left, the father has one copy of
the dominant gene and one copy of the recessive gene. The mother has two copies
of the dominant gene. Each parent can contribute just one gene to the child.
The four children showed on the lower left represent the probabilities (not the
actual children) for the combinations that can result from their parents. The
children on the far left received the recessive gene from their father and the
dominant gene from their mother, and are therefore carriers. For any child born
to these parents, there is a 50 percent chance that the child will be a
carrier. Since none of the children can inherit two copies of the recessive
gene, none of the children will develop the disease. When both parents are
carriers, however, as shown by the couple on the right, there is a 25 percent
chance that any child born has the disease, a 50 percent chance that a child is
a carrier, and a 25 percent chance that a child does not have the disease and
is not a carrier.
Microsoft ® Encarta ® Encyclopaedia 2004. ©
1993-2003
Expecting couples concerned
about the health of their unborn baby may request genetic counselling to learn
if the baby is at risk for a disease. A pregnant woman may worry that she has
been exposed to factors that can hurt the development of her foetus, such as infectious
diseases, medications, alcohol, non-medical drugs, or radiation. Genetic
counselling can prove useful when adopting a child. Parents interested in adopting a child whose biological parent or grandparent has an inherited
condition may seek counselling to determine if this family history is likely to
affect the child.
The parents of a newborn diagnosed
with a genetic disease may ask a genetic counsellor to explain the progression
of the disease and describe the types of treatments required to keep their baby
healthy. Infertile couples or those who have experienced two or more
miscarriages may pursue genetic counselling to learn whether a genetic
condition may be responsible for their reproductive difficulties.
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B
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People with a Family History of Disease
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Rights Reserved.
Family
Pedigree
Family pedigrees trace
specific genetic characteristics through three or more generations. Pedigrees
such as this one, which depicts the inheritance of a gene associated with
cystic fibrosis, help genetic counsellors to identify, which individuals in a
family are at risk of either inheriting a genetic disorder or being a carrier
for a disorder. Whereas only Africans have the Sickle Cell disease, mixed
marriages could produce a variety of mutations that we are still researching
into. Colour blindness, on the other hand is not common in and their
descendants Africans!
Hafani Organisation
& Microsoft ® Encarta ® Encyclopaedia 2004. © 1993-2003
Genetic counselling can
also help people who have a family history of common diseases, such as cancer,
heart disease, or mental illness. Although these diseases are not routinely
considered genetic disorders, they often have a hereditary component when they
affect multiple members of a family. A genetic counsellor may recommend that
family members set up regular physical examinations or screening tests with a
medical specialist. These regular examinations can detect health problems
early, when the conditions may be easier to treat. Counselling may also help
family members make informed decisions about diet, exercise, and surgery
options that can help reduce the chance that the condition will develop, or
that can lessen the condition’s severity.
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Ethnic Groups at Higher Risk for Disease
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Some people seek genetic
counselling to learn about genetic disorders that occur more frequently in
their ethnic group. For instance, Tay-Sachs disease is more common among
certain populations of Jews from eastern Europe, and sickle-cell anaemia occurs
primarily in African Americans.
DIAGNOSING
A GENETIC CONDITION
The genetic counsellor’s
top priority is to help accurately diagnose a genetic condition. In some cases,
clients may be referred to a counsellor after a physical examination or medical
tests suggest an inherited disorder. In this case, the counsellor must evaluate
the reliability of the diagnosis and determine if additional tests or second
opinions from medical specialists are needed to confirm it. In other instances
the counsellor may aid in making the initial diagnosis by arranging special
tests, such as blood tests that determine the presence of a disease-causing
gene or chromosomal abnormality, or prenatal screening (such as an ultrasound)
that evaluates the health of a foetus.
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Inheritance Patterns
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As part of the diagnosis
process, genetic counsellors educate clients about the inheritance patterns of
suspected genetic disorders, many of which are rare conditions unfamiliar to
most people. Genetic disorders typically arise from single gene mutations or
chromosomal abnormalities that are transmitted from generation to generation.
Each individual inherits
two versions of every gene, one from the mother and one from the father.
Occasionally one gene in a pair becomes altered through a process called
mutation, and this mutated gene passes from parent
to child in a predictable pattern. In some cases, the mutated gene inherited
from one parent dominates, expressing
itself even when a normal gene inherited from the other parent is present. A parent
who has the mutated gene develops the disease and has a 50 percent chance of
passing the faulty gene on to his or her child. Examples of diseases caused by
dominant genes include neurofibromatosis and Huntington’s disease.
Recessive
genes, such as sickle-cell anaemia and cystic fibrosis, cause other diseases.
Such diseases develop when both genes of a pair have a mutation. Two parents who each carry a mutated recessive
gene for the same disease have a 25 percent chance with each pregnancy of
having a baby who will develop the disease. A parent
may unknowingly carry a mutated recessive gene for a particular disease without
suffering any symptoms of the disorder.
Single gene mutations
may occur on the sex chromosomes, the pair of chromosomes in each cell that
determine the sex of an individual. Females’ sex chromosomes consist of two X
chromosomes, and males have one X and one Y chromosome. A female with a
recessive mutated gene on one X chromosome usually has a normal gene on her
other X chromosome, and the normal gene masks the effects of the mutated gene.
As a carrier of the mutated gene, the female has a 50 percent chance of passing
the mutated gene on to her children. Daughters who inherit the altered gene are
usually unaffected because they have a normal gene on their other X chromosome.
But when a male inherits a mutated gene on the X chromosome from his mother, he
does not have a normal second copy of the gene on the Y chromosome to mask the
effects of the mutated gene. Diseases that result from such X-linked gene
mutations include haemophilia and Duchenne muscular dystrophy.
Chromosomal abnormalities
affect the number of chromosomes, the size or appearance of certain
chromosomes, or the arrangement of chromosomes in cells. One example of a
disease associated with the presence of an extra chromosome is Down syndrome,
which causes mental retardation and physical abnormalities.
Turner
syndrome, a condition that affects females, results when one of the two X
chromosomes is partially or completely missing. In some cases, a healthy parent may carry a chromosomal rearrangement,
known as a translocation, in which a piece of one chromosome is attached to
another.
Another
abnormality, known as inversion, occurs when a piece of chromosome gets turned
around 180 degrees from its normal position. People who have chromosomal
rearrangements may experience infertility or repeated miscarriages.
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Family Medical History
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Genetic counsellors gather
information about a client’s family medical history to determine if an
inherited disorder exists within a family. Genetic counsellors record a
client’s medical family history for at least three generations and present the
information as a diagram, called a pedigree.
A pedigree
uses symbols to form a family tree—circles represent females, squares indicate
males, and horizontal and vertical lines connect the circles and squares to
show how family members relate to each other.
The pedigree details significant
family and health information for each family member, including birth and death
dates, cause of death, miscarriages, stillbirths, and medical conditions, such
as cancer, diabetes, heart disease, birth defects, genetic conditions, and
mental retardation.
Pedigrees
also note the ethnic, racial, or geographic origins of the client’s ancestors
to alert the counsellor to genetic disorders prevalent among certain groups of
people.
SOME GENETIC DISORDERS DETECTED PRE-NATALLY
Genetic disorders may result from defects in
genes or from chromosomal abnormalities. Prenatal tests, performed early in a
woman’s pregnancy, can identify a foetus with a genetic abnormality.
Prenatal diagnosis using amniocentesis or
Chorionic villus sampling pose a slight risk to the foetus, and health
professionals generally recommend these tests only if the mother or father has
a family history of a genetic disorder or an increased risk of having a child
with a chromosomal abnormality.
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Genetic Disorder
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Incidence*
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Congenital adrenal hyperplasia
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10 per 100,000 people
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Cystic fibrosis
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31 per 100,000 live Caucasian births;
11 per 100,000 live Hispanic births; 7 per 100,000 live African American births; 3 per 100,000 live Asian births |
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Duchenne muscular dystrophy
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20 to 30 per 100,000 males
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Haemophilia A
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20 per 100,000 male live births
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Huntington's disease
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10 per 100,000 people
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Polycystic kidney disease (adult type)
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100 to 250 per 100,000 people
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Sickle-cell anaemia
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250 per 100,000 African Americans
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Tay-Sachs disease
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28 per 100,000 Ashkenazic Jews worldwide;
28 per 100,000 Cajuns |
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Thalassemia
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1 per 100,000 people in North and South
America
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*Incidence
rates are for populations most affected in the United States.
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Microsoft ®
Encarta ® Encyclopaedia 2004. © 1993-2003
Genetic counsellors use
a family medical history to identify patterns of disease inheritance and to
predict the probability that other family members will inherit a disease. A
family medical history may also identify the causes of diseases that do not
have a genetic basis. Disease may occur among individuals who share a certain
lifestyle habit, such as smoking cigarettes or excessive use of alcohol.
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Diagnostic Testing
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Genetic counsellors may
suggest that a client undergo certain tests that can analyse the genetic
information in a person’s cells. Some tests can help identify individuals who
carry genes for recessive genetic disorders. Other tests can identify
disease-causing genes or chromosomal disorders in a foetus. Some tests can
determine if a person has a high probability for developing an inherited
disorder later in life.
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Carrier Screening
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Carrier screening tests
can determine if an otherwise healthy person carries a recessive gene for a
disease that is common in certain ethnic groups, such as Tay-Sachs disease in
Jews from Eastern Europe. The client usually provides a blood sample or a
sample of cells scraped from the inside of the cheek. These cells are examined
in a laboratory to determine if the person has a mutated gene. Such screening
helps parents make reproductive
choices.
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Prenatal Testing
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In cases in which a woman
is already pregnant and concerned for the health of her baby, genetic
counsellors may suggest that she undergo prenatal tests that can identify
health problems in the foetus. For the great majority of mothers, who have
normal test results, prenatal testing reassures that the foetus is healthy. If
prenatal tests indicate that a foetus has a disorder, genetic counsellors
provide parents with information about
the disease as well as the medical and educational needs of children who have
the disorder. Counsellors can also help parents
determine if the option to terminate a pregnancy is in harmony with the
couple’s values.
Physicians use several
methods to diagnose genetic abnormalities in a foetus. Ultrasound imaging uses
sound waves to create an image of the foetus. Ultrasound monitors the growth
and development of the foetus and can identify abdominal wall defects, cleft
lip, and some heart defects. A blood test can identify whether a mother’s blood
contains a high level of the protein alpha-fetoprotein, an indication that the
baby is at risk for spinal cord abnormalities.
© Microsoft Corporation. All
Rights Reserved.
Prenatal
Testing
Two types of medical tests
may be used early in a woman’s pregnancy to determine if her foetus has a
defective gene or a chromosomal abnormality. Both procedures remove cells
surrounding the developing foetus. The cells obtained have the same genetic
makeup as the foetus and can be tested for genetic abnormalities. In Chorionic
villus sampling, a doctor removes tissue from the Chorionic villi, finger-like
projections that are part of the developing placenta, between 10 and 12 weeks
of pregnancy. Using ultrasound guidance, the doctor inserts either a needle
through the woman’s abdominal wall or a thin, hollow tube called a catheter
through her cervix to reach the Chorionic villi. Using a syringe the doctor
suctions out cells. Amniocentesis is usually performed between 15 and 17 weeks
of pregnancy. In this procedure, a doctor uses ultrasound guidance to insert a
needle through the abdominal wall into the amniotic fluid surrounding the
foetus. Cells from the amniotic fluid are removed using a syringe. Both
procedures pose a slight risk for the developing foetus, and health
professionals recommend these tests only in cases in which a mother or father
has a family history of a genetic disorder or a known risk for chromosomal
abnormalities.
Microsoft ® Encarta ® Encyclopaedia
Chromosomal analysis is
performed on foetal cells, usually when the mother is over age 35 and therefore
most at risk for bearing a child with chromosomal abnormalities. Chorionic
villus sampling analyses the cells from the placenta, the organ that supplies
nutrients and oxygen to the foetus and removes waste. Testing performed on
cells from the amniotic fluid, the protective liquid that surrounds the foetus
in the uterus, is known as amniocentesis.
A genetic counsellor may
recommend that the mother undergo percutaneous umbilical blood sampling (PUBS).
In this test, a small blood sample is removed from the umbilical cord of the
foetus. From that sample, a physician can identify certain blood diseases and
other disorders that prevent normal foetal growth.
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Predictive Testing
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Genetic counsellors may
assist clients in decisions about predictive testing, which identifies if a
person has one or more altered genes whose effects typically do not appear
until later in life. There are two types of predictive testing: pre-symptomatic
tests and susceptibility tests. When an individual’s parent or grandparent develops an illness such as Huntington’s
disease, the individual may fear developing the same disease later in life. In
such a case, a genetic counsellor may arrange for the client to undergo
pre-symptomatic testing, which analyses DNA in the blood to determine whether
the person has the altered gene that causes Huntington’s disease. If the
altered gene is present, the genetic counsellor can predict with certainty that
the client will develop Huntington’s disease. However, predictive testing
cannot predict the age a person will develop the disease.
Before recommending that
clients undergo pre-symptomatic testing, a genetic counsellor prepares clients
to accept the test results. Many diseases that develop late in life cause
severe disability or lead to premature death. Clients must be prepared to live
with the knowledge that they could eventually develop a fatal disease. Some
people choose not to have testing, while others prefer to know their risk so
that they can make decisions about having children or make financial or
care-giving arrangements before symptoms develop.
Susceptibility tests determine
the presence of a gene or group of genes that may predispose a person to
develop a particular health problem later in life. Unlike pre-symptomatic
tests, these tests only identify a higher probability that a particular
disorder will develop. They do not provide a certain diagnosis. Susceptibility
tests may reveal a risk for some types of cancer, heart disease, diabetes
mellitus, and Alzheimer’s disease. If a woman learns that she has a gene
closely linked to breast cancer, a genetic counsellor can refer her to a breast
cancer specialist who can monitor the woman’s health. If the woman does develop
cancer, the close monitoring will enable the specialist to detect it in its
earliest stages, when the disease is easiest to treat.
CHOOSING
A COURSE OF ACTION
After identifying a disease
or estimating the probability that a disease will develop, the genetic
counsellor helps individuals and their families choose a course of action to
cope with the genetic condition. Genetic counselling requires sensitivity to a
client’s needs and belief systems. Individuals have varying life experiences,
social attitudes, and religious values that will influence their thinking about
testing and medical issues. For example, a couple may not mind coping with the
disabilities of a child with an inherited disease, or their religious values
may prevent them from considering abortion. These couples may decide against
prenatal testing. In other cases, a couple who has already had a child with a
terminal illness may not want to have any more children. The couple may choose
to undergo sterilization procedures that will permanently prevent pregnancy.
Keeping these differing
views in mind, genetic counsellors do not tell a client what to do. Instead,
they use what is known as a nondirective approach. If a client asks a genetic
counsellor, “What would you do if you were me?” the counsellor may reply,
“Other individuals in your situation have considered the following options...”
This neutral response ensures that the client controls decision-making.
Genetic counsellors help
their clients take action to deal with the immediate or potential challenges
presented by a genetic disorder. This may include helping couples that do not
want a child choose a contraceptive option or arrange for sterilization
surgery.
© Microsoft Corporation. All
Rights Reserved.
Correcting
Genetic Diseases
Gene therapy may someday be
able to cure hereditary diseases, such as haemophilia and cystic fibrosis,
which are caused by missing or defective genes. In one type of gene therapy,
genetically engineered viruses are used to insert new, functioning genes into
the cells of people who are unable to produce certain hormones or proteins
necessary for the body to function normally.
Counsellors
may help infertile couples find an adoption agency. Genetic counsellors may act
as consumer advocates, helping families find community resources, such as
special education programs for children born with genetic disorders that cause
learning disabilities. They develop strategies to provide round-the-clock care
for a person with a severely disabling condition. In addition to practical
considerations, counsellors address the emotions of parents faced with the devastating news that their child has a
deadly illness or of siblings who do not have a disorder themselves but may be
troubled by the problems facing other family members. Through such efforts,
genetic counsellors help families make the best possible adjustment to the
physical, economic, social, and emotional burden of the disorder.
Contributed By: Robin L. Bennett,
Chris A. Ezike & Nkechi N. Mbaezue
GENETIC ENGINEERING AND ITS USE IN
MEDICINE
Definition:
Genetic Engineering is the alteration of an organism's genetic or hereditary material to
eliminate undesirable characteristics or to produce desirable new ones.
Genetic engineering is used to increase plant and animal food production; to
diagnose disease, improve medical treatment, and produce vaccines and other
useful drugs; and to help dispose of industrial wastes. Included in genetic
engineering techniques are the selective breeding of plants and animals,
hybridisation (reproduction between different strains or species), and
recombinant DNA.
Production
of Medicines
In 1982, the United States Food and Drug
Administration (FDA) approved for the first time the medical use of a
recombinant DNA protein, the hormone insulin, which had been cloned in large
quantities by inserting the human insulin gene in Escherichia coli bacteria. Previously, this hormone, used by
insulin-dependent people with diabetes, had been available only in limited
quantities from hogs. Since that time, the FDA has approved other genetically engineered
proteins for use in humans, including two cloned in hamster cell cultures: Tissue plasminogen activator (tPA), an
enzyme used to dissolve blood clots in people who have suffered heart attacks,
and Erythropoietin, a hormone used to
stimulate the production of red blood cells in people with severe anaemia.
Scientists also have employed recombinant DNA
techniques to produce medically useful human proteins in animal milk. In this
procedure, the human gene responsible for the desired protein is first linked
to specific genes of the animal that are active only in its mammary (milk-producing) glands. The egg
of the animal is then injected with the linked genes. The resulting transgenic
animals will have these linked genes in every cell of their body but will
produce the human protein only in their milk. The human protein is finally
extracted from the animal's milk for use as medicine. In this way, sheep's milk
is used to produce Alpha-1-antitrypsin,
an enzyme used in the treatment of emphysema; cow's milk is used to produce Lactoferrin, a protein that combats
bacterial infections; and goat's milk is used as yet another way to produce
tPA, the blood-clot-dissolving enzyme also cloned in hamster cell cultures.
Recombinant DNA technology also is used in
the production of vaccines against disease. A vaccine contains a form of an
infectious organism that does not cause severe disease but does cause the
body's immune system to form protective antibodies against the organism. When a
person is vaccinated against a viral disease, the production of antibodies is
actually a reaction to the surface proteins of the coat of the virus. With
recombinant DNA technology, scientists have been able to transfer the genes for
some viral-coat proteins to the vaccinia, or cowpox, virus, which was used
against smallpox in the first efforts at vaccination, and which gave the
process its name. Vaccination with genetically altered vaccinia is now being
used against hepatitis, influenza and herpes simplex viruses. Genetically
engineered vaccinia is considered safer than using the disease-causing virus
itself and is equally as effective.
Gene
therapy
Gene therapy is a medical management of a
patient in which a healthy gene can be directly inserted into a person with a
malfunctioning gene. This is perhaps the most revolutionary and promising of
recombinant DNA technology, but many problems remain to be solved in getting
the healthy gene into human cells. Although the use of gene therapy has been
approved in more than 100 clinical trials for diseases such as cystic fibrosis,
emphysema, and muscular dystrophy, there have yet been no cures.
Controversies:
Public
reaction to the use of recombinant DNA in genetic engineering has been mixed.
The production of medicines using genetically altered organisms has generally
been welcomed. However, critics of recombinant DNA fear that the pathogenic, or disease-producing,
organisms used in some recombinant DNA experiments might develop extremely
infectious forms that could cause worldwide epidemics. In an effort to prevent
such an occurrence, the National Institutes of Health (NIH) has established
regulations restricting the types of recombinant DNA experiments that can be
performed using such pathogens.
Transgenic
plants also present controversial issues. Environmentalists fear that the
transgenic plants could spread and eliminate existing species. In addition, it
has now been proved that allergens (see
Allergy) can be transferred from one food crop to another through genetic
engineering. In an attempt to increase the nutritional value of soybeans, a
genetic engineering firm experimentally transferred a Brazil nut gene producing
a nutritious protein into the soybean plant. However, when a study found that
the genetically engineered soybeans caused an allergic reaction in people
sensitive to Brazil nuts, the project was cancelled. Questions also have been
raised concerning the morality of producing transgenic organisms. In addition,
some critics object to the patenting of genetically altered organisms because
it makes the organisms the property of particular companies.
Conclusion:
The lack of a
completely successful gene therapy programme has concerned many people,
including a number of scientists. Medical scientists, in particular feel that
before additional clinical trials are conducted, more must be understood about
the factors that control whether a particular vector can enter a given type of
cell and become incorporated into its genetic material. However, the wishes of
many people awaiting gene therapy, as well as the commercial interests of
companies, have created great pressure both to continue existing programmes and
to begin new ones. The current challenge posed by HIV/AIDS is a case in point,
demonstrating the urgent need to continue the search for effective remedies.
Contributed
By: Louis Levine and Kenez Danmbaezue
FOR HAFANI PROJECT 007 @
UNTH, ENUGU on HIV-MANAVEN 2001 – 2003.
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