Metro Plus
Bangalore
Chennai
Coimbatore
Delhi
Hyderabad
Kochi
Madurai
Mangalore
Pondicherry
Tiruchirapalli
Thiruvananthapuram
Vijayawada
Visakhapatnam
All in the genes
|
Planning to have a baby? If you have a family history of an inherited disease, or other risk factors for a genetic condition, it is wise to consult a genetic counsellor
|
PHOTO: k. ananthan
COUNSELLING TO THE RESCUE For a healthy baby
Shreyasee has a baby with thalassemia major. Seeing her child having to undergo repeated transfusions, she and her husband want to know if they can have an unaffected baby. They want to understand the risk of having another baby with thalassemia majo
r.
Susheela had a baby with cystic fibrosis. The child died at the age of five. She and her husband are worried. Will they have another baby with cystic fibrosis?
Shreyasee and Susheela both have had babies with a genetic disorder. They need to be seen by a genetic counsellor. In the 21st Century, there is more and more knowledge being uncovered about the genetics of common diseases. If there is a genetic disorder in the family, a genetic counsellor helps you understand your risk of having a baby with that disorder. If a couple has already had a child with an inherited birth defect, genetic counsellors can help them understand what their chances are of having another baby with the same genetic disorder. They can also help them learn what testing, surveillance or prevention strategies are available.
Who is a genetic counsellor?
A genetic counsellor is a person who has studied genetic diseases and how these diseases run in families. The genetic counsellor can help a person and the family understand the risk for genetic conditions (such as cystic fibrosis, thalassemia, hemophilia, muscular dystrophy or Down syndrome), educate the person or family about that disease, and assess the risk of passing those diseases on to children.
A genetic counsellor may be a doctor who has specialised in genetic counselling or somebody who has studied genetics and has had training in counselling. They work with families to identify members who are at risk.
Do you need to see a genetic counsellor?
If you have a genetic condition, have a family history of an inherited disease, or have other risk factors for a genetic condition or birth defect, you may benefit from consulting a genetic counsellor. If your family history indicates the possibility of an inherited disease, your obstetrician may refer you to a genetic counsellor.
How does genetic counselling help?
The genetic counsellor takes a detailed family history. This allows her to draw up a family tree or pedigree chart which helps clarify the way the genetic disorder is being passed from generation to generation. This diagram also helps to determine your risk for inheriting that particular disease. If you do have an increased risk, the counsellor will make sure that you understand the basic genetic concepts that affect how the disease runs in families, educate you about the disease itself, and explain the level of risk for you and your family.
Let us take the case of Shreyasee and her husband. To assess their risk the genetic counsellor discussed their family history. Shreyasee came from a community where there was a lot of intermarrying among close relatives. This increased the chance of both being carriers of the disease. A carrier is a person who has both a normal and a defective gene. The carrier is therefore normal in all ways but can pass on the disease to the baby. The genetic counsellor tested Shreyasee and her husband to find out if they were carriers of thalassemia. After DNA testing, both were found to be carriers.
The counsellor told them that they had a 25 per cent (1 in 4) chance of having an unaffected (normal) baby, a 25 per cent chance of having an affected baby and a 50 per cent chance of a baby who will be a carrier. With their next pregnancy, Shreyasee underwent a chorionic villus sampling. This is a test where a small amount of tissue is aspirated from the forming placenta. The test showed that the baby was a carrier but did not suffer from the disease. This meant that the baby had inherited a defective gene from one parent and a normal gene from the other parent. The baby was born and has continued to stay healthy.
GITA ARJUN
Printer friendly
page
Send this article to Friends by
E-Mail
Metro Plus
Bangalore
Chennai
Coimbatore
Delhi
Hyderabad
Kochi
Madurai
Mangalore
Pondicherry
Tiruchirapalli
Thiruvananthapuram
Vijayawada
Visakhapatnam
|
