GENETIC COUNSELLINGGENETIC COUNSELLING

INTRODUCTIONINTRODUCTION :-

Genetic counselingGenetic counseling is the process of evaluating family history & medical

records,ordering genetic tests, evaluating the results of this investigation & helping parents

understand & reach decisions about what to do next. Genetic test are done by analyzing small

samples of blood or body tissues. They determine whether you or your partner or your baby carry

genes for certain inherited disorders.

WHO ARE GENETIC WHO ARE GENETIC COUNSELLERS ?COUNSELLERS ?

They are postgraduates health professionals with a graduate diploma or Master’s in genetic counselling.

They have an experience in the areas of medical genetics and counselling.

They identify family at risk, investigates the problems present in the family, interpret information about the disorder, analyze inheritance patterns and, risk of re-occurrence & review available option with the family.

They serves as educators and resource people for other health care professionals and for general public.

Some work in administration capacities. Many engage themselves in research activities related to the field of

medical genetics & genetic counselling.

WHAT IS THE ROLE OF GENETIC WHAT IS THE ROLE OF GENETIC COUNSELLING ?COUNSELLING ?

Genetic Counsellors provide genetic information. It is their counselling skills, including their ability to empathically connect with their patients that leads to demands for their skills.

Good Genetic Counsellor have many strengths. They make their clients’ best interest their foremost priority and are keenly attuned to complex professional and ethical challenges.

Genetic Counsellor use non-directive counselling method to provide the best service to those who need them.

If directive counselling are used, the counsellor tends to give advice, make decision, be coercive, persuasive, influencing, directing and controlling.

If non-directive counselling methods are employed the counsellor communicates, enables, explores, encourages, informs, offers choices, discusses,promotes autonomy ,is empathic, non-judgmental, and respectful of the client.

To develop a mutual relationship with the client, to understand her or him, to relieve any psychological distress, promote a sense of control, and help find solution to specific problems.

They need to be able to : assess the client’s strengths, values and needs;provide an individualization and flexible counselling style to suite each client’s need and agenda;develop an awareness of self;and attend to their own inner life.

WHO NEEDS GENETIC COUNSELLING ?WHO NEEDS GENETIC COUNSELLING ?

Those who can benefit from genetic counseling include those who have a history of:

A known genetic disorders e.g. Cystic Fibrosis, Hemophilia, Down’s syndrome

Birth defects eg. Spina Bifida, Cleft Lip and Palate, Congenital heart disease, club foot

Inherited Cancers e.g. Breast and Bowel Cancers Intellectual disability Hearing or visual disability Infertility or multiple miscarriages or infant deaths Genetic defects occurring frequently in special ethnic and

rational groups e.g. Tay-Sac disease, Sickle cell Anemia, Thalassemia.

WHAT HAPPENS DURING : WHAT HAPPENS DURING : “GENETIC COUNSELLING “GENETIC COUNSELLING

SESSION”SESSION”

To determine why the patient or family is seeking genetic counselling, To identify what information they wish to get out of the session. In session , counsellor ask for any genetic disorder, multiple

miscarriages and early or unexplained death of relative (if any). Counsellor looks for medical records including ultrasound, parental

test results and other diagnosis which have been made in the past. An accurate pedigree chart is made by seeking information from the

patients, their family members, cousins, in –laws, sibling and grandparents to find out any inherited genetic disorder is there.

And finally when results come counsellor will encourage you to come in for a discussion and will explain and advice over a particular problems.

WHAT IS A PEDIGREE CHART ?WHAT IS A PEDIGREE CHART ? Pedigree is used to help make a diagnosis of genetic

disease. To determine a person’s risk of developing a genetic

disease. Contains vital medical information like birth date, age of

death, cause of death, health problems and results of genetics test.

To estimate the risk of relative face to develop a genetic disease or have a child with a genetic disease.

To determine the risk of having a child with genetic disease.

On the basis of information gathered from the first degree relatives i.e. parents&sibling , second degree of relatives i.e. aunts & uncles and third degree relatives i.e. cousins & grand parents, a pedigree chart is made.

SYMBOLS USED IN HUMAN PEDIGREE SYMBOLS USED IN HUMAN PEDIGREE ANALYSIS :-ANALYSIS :-

SYMBOLS EXPLANATION SYMBOLS EXPLANATION

MALE AFFECTED MALE&FEMALE

FEMALE HETEROZYGOTE

MATING CARRIER

PARENTS & CHILDREN(1BOY:1

GIRL)

METHOD OF IDENTIFYING

PERSONS

DIZYGOTIC TWINS (MALE&FEMALE)

ABORTION OR STILL BORN

MONOZYGOTIC TWINS(MALE)

DEATH

SEX UNSPECIEFIED

PROPOSITUS (PROBAND)

NO.OF CHILDREN OF SEX INDICATED

CONSANGUINEOUS MARRIAGE

1 2 3

2 3

WHAT HAPPENS DURING –WHAT HAPPENS DURING – “ “ POST – COUNSELLING SESSION POST – COUNSELLING SESSION

”” A family having problems and difficulty will have to decide

what to do next. Genetic Counsellor helps you to the difficulties and

uncertainties you face and understand your problems. Family have to prepare themselves for the challenges they

will face due to the disorder. Counsellor appreciates the way heredity contributes to the

disorder risk of re-occurrence. Counsellor makes the family understand the alternatives

for dealing with the risk. Counsellor make them choose a course of action and make

best possible adjustment.

IN SHORTIN SHORT GENETIC COUNSELLING IS :- GENETIC COUNSELLING IS :-

Determine the facts : Diagnosis, etiology, and inheritance patterns, prognosis, natural history, treatment and re-occurrence of risk.

Transmitting the information : To those requesting it in a sensitive, culturally appropriate, understandable way.

Supporting the decision : Supporting the decision making process of the couple.

Genetic counselling : It is non-directive.

PRE-REQUISITES OFPRE-REQUISITES OF GENETIC COUNSELLING IS :- GENETIC COUNSELLING IS :-

Detailed family history. Accurate diagnosis. Understanding the medical aspect of the disorder

(etiology, natural history, treatment, prognosis, burden ). Understanding the inheritance pattern ( recurrence risk ). Understanding the psycho-social impact of the

information. Training / experience in counselling techniques. Understanding the concepts of health / disease / health

care in the appropriate cultures.

CONCLUSION :-CONCLUSION :-

In conclusion , Genetic Counsellors are gatekeepers between genetic information and technology and the lives of those for whom the science is applied. In this role the counsellor must balance attention to the science with attention to the psychosocial concerns of the clients. The counsellor must be well grounded in the principals and practice of psychosocial assessment and intervention and in the socio-cultural contexts within which Genetic Counselling functions and clients live their lives

GENETIC DISORDERSGENETIC DISORDERS

INTRODUCTION :-INTRODUCTION :-

Genetic Disorder are medical conditions caused by mutations a or a set of

genes. Mutations is any heritable change in the genetic make up of an individual other than that

which may be caused by the simple recombination of the genes. In other words we can say mutations are the changes in the DNA sequence of the gene thus this mutated genes causes genetic disorders.

CATEGORIES OF CATEGORIES OF GENETIC DISORDERS :-GENETIC DISORDERS :-

GENETIC DISORDERS ARE CATEGORIZED INTO GENETIC DISORDERS ARE CATEGORIZED INTO FOUR FOUR CATEGORIES :-CATEGORIES :- Chromosome Abnormalities :- In some disorders, entire or large segments of them,

are missing, duplicated, or otherwise altered. Down Syndrome and Turner's Syndrome are examples of this type of disorder. I

  Single-Gene Disorders :- Some disorders result when a mutation causes the protein

product of a single gene to be altered or missing. An example of this kind of disorder is Sickle Cell Anemia

  Multi-factorial Disorders :- Multi-factorial disorders result from mutations in multiple

genes, often coupled with environmental causes. The complicated bases of these diseases make them difficult to study and to treat. Heart Disorder, Diabetes and Cancer are examples of this type of disorder.

  Mitochondrial Disorders :- These relatively rare disorders are caused by mutations in

non-chromosomal DNA located within sub cellular organelles, the mitochondria. There are multiple copies in a single cell's cytoplasm, all transmitted by the mother in the ovum.

 

GENETIC BASIS OF THE GENETIC BASIS OF THE DISORDERS DUE TO MUTATIONSDISORDERS DUE TO MUTATIONS

SEX - LINKED RECESSIVE SEX - LINKED RECESSIVE MUTATIONS :-MUTATIONS :-

Pedigree pattern of a X-linked recessive disorder tends to be oblique because the transmission of such a condition from a male to his grandson is through his carrier daughter. In females, a sex-linked recessive condition express only in homozygous condition whereas,in Males it expresses in hemizygous from as Y-chromosomes lacks the genes present on the X-chromosomes.father to son transmission is absent in man. E,g.Colorblindness,Hemophilia ,Ichthyosis,Hunter syndrome .

A TYPICAL PEDIGREE OF A TRAIT DUE TO SEX-LINKED RECESSIVE GENE.

SEX – LINKED DOMINANT MUTATIONS SEX – LINKED DOMINANT MUTATIONS :-:- In case of a condition due to sex-linked dominant gene, both males and femalesare

affected & both male and female transmit the disorder to their offspring, just as in autosomal dominant condition.affected males transmit the condition to none of his sons but to all of the daughters. E.g. Vitamin-d resistant rickets, low blood phosphate.

A TYPICAL PEDIGREE OF A TRAIT DUE TO SEX-LINKED DOMINANT GENE.

AUTOSOMAL DOMINANT AUTOSOMAL DOMINANT MUTATIONS :-MUTATIONS :-

This is a salient feature of a pedigree having a disorder due to autosomal dominant mutation. The condition typically occurs in every . Unaffected individuals never transmit the condition to their offspring. Two affected parents may have unaffected children. One-fourth of children of parents heterozygous for such a disorder are normal.when one of the two parents is affected, the condition may pass on to one-half of the children of affected individual. E.g. Brachydactyly, Achondroplasis,Hurlington’s Chorea, Retinoblastoma.

A TYPICAL PEDIGREE OF A TRAIT DUE TO AUTOSOMAL DOMINANT GENE.

AUTOSOMAL RECESSIVE AUTOSOMAL RECESSIVE MUTATIONS :-MUTATIONS :-

This condition appears in the progeny of two unaffected ( heterozygous;carrier ) individuals. About one-fourth of the children are affected. Two affected individuals cannot have an unaffected child.Condition occurs with equal frequency in males and females. Autosomal recessive disorders are frequently revealed in cousins marraiges. E.g. Tay-Sachs disease, Cystic Fibrosis, Phenylketonuria, Alkaptonuria, Albinism.

A TYPICAL PEDIGREE OF A TRAIT DUE TO AUTOSOMAL RECESSIVE GENE.

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Catalogue of Variants and Anomalies.Brewster, T. and P. Gerald (1978); Chromosomes Disorders

Associated with Mental Retardation.Culliton, J. (1989); Gene Test Begins.Hilton,B. ,D.Callahan, M.Harris ,P. Condliffe, and B. Berkley

(1973); Genetic Counselling and The Use of Genetic Knowledge.

Krontiris ,T.G.(1995); Minisatellites and Human Disease.Mc Kusick, V.A.(1994); Human Genetics.Stern, C.(1997); Principles of Human Genetics.Warburton, D, J.Byme, and N.Canki.(1990); Chromosomal

Anomalies and Prenatal Development.