Genetic counselling

BY: AMAL SRGEWA

THE UNIVERSITY OF SHEFFIELD 2010

OUTLINE

General concept of genetic Genetic screening Genetic counselling applications Pre marriage genetic counselling Genetic counselling ethics

General concept

Genetic definition: branch of science which studies genes and the pattern of inheritance of particular diseases.

Inheritance: The passing of familial elements from one generation to the next.

DNA : molecule encodes the genetic information.

Gene: gene is the functional subunit of DNA and contain instruction for making protein.

Genetic pedigree: a diagrammatic representation of diseases history in a family up to 3rd degree relative.

Brief history George Mendel ( the father of genetic). 1866

Lamb dolly cloning 1996

Pattern of inheritance

Chromosome: A structure within the cell that deliver the genetic material as DNA.

Pattern of inheritance

Human cell contain 23 pairs of chromosomes. 22 pairs autosomal and one pair sex chromosomes.

23chromosomes inherited from mother and 23 chromosomes from father.

Sex chromosomes: XX for female and XY for male.

Pattern of inheritance

Mutant gene: means abnormal gene which can not perform its function in proper way.

Affected individual: individual who is known to has disease.

Carrier individual: individual who appear normal but has one copy of mutant gene.

Pattern of inheritance

Autosomal dominant

Autosomal recessive

X-Linked inheritance

Multifactorial inheritance

Genetic screening

Definition: A search in apparently normal population for individual with abnormal genes which increase their risk or their offspring of being affected by a disease.

Types of genetic screening

1. Carrier identification

2. Prenatal diagnosis

3. Newborn screening

4. Forensic screening ( paternity test)

Genetic counselling Definition: providing of information regard

health and support by a specialist doctor “a geneticist” to client (a person who perform genetic test).

Function of genetic counselling session: Provide information Available solution Help person to understand and cope with his

condition Testing the risk of recurrance

Who seek genetic counselling session

Couple who are planning marriage

Couple who are planning a pregnancy

Newly diagnosed patient

A person who concern about a particular disease run in his family

Down syndrome

osteopetrosis

procedure

A cell sample is taken from both couple and analysed in the laboratory.

Counsellor help couples to understand their relative risks of transmitting a genetic defect to their offspring.

Couples decide which solution to choose.

Genetic counselling ethics

Respect the right of individual

Non- directive approach

Keep privacy of individual and family

Maintain the communication between counsellor and his client

conclusion

Many diseases have genetic root

The genetic screening is an essential issue in most stages of the life.

Genetic counselling aim is to bridge the gap for people between genetic field complexity and their life.

Any question