Table of Contents
- 1 Do both parents need to be carriers for Tay-Sachs?
- 2 Who is at risk for Tay-Sachs?
- 3 Can Tay-Sachs disease be detected before birth?
- 4 How long is the average lifespan of a person with Tay-Sachs?
- 5 How does Hex-a gene cause Tay Sachs disease?
- 6 What are the chances of inheriting an autosomal dominant disorder?
Do both parents need to be carriers for Tay-Sachs?
Both parents must be TS carriers to be at risk for a baby with TS. If one parent has a negative (normal) test result, the chance that a baby will have Tay-Sachs disease is very small. Testing can be done at any Kaiser Permanente laboratory. A genetic counselor will let you know how to arrange testing.
Who is at risk for Tay-Sachs?
Risk factors for Tay-Sachs disease include having ancestors from: Eastern and Central European Jewish communities (Ashkenazi Jews) Certain French Canadian communities in Quebec. Old Order Amish community in Pennsylvania.
What is the chance of a parent having two copies of the Tay-Sachs allele?
Tay-Sachs disease is caused by a defective gene on chromosome 15. When both parents carry the defective Tay-Sachs gene, a child has a 25% chance of developing the disease. The child must receive two copies of the defective gene, one from each parent, in order to become sick.
What are the odds of being a Tay-Sachs carrier?
If both parents are carriers and their child inherits the defective Hex-A gene from each of them, the child will have Tay-Sachs disease. When both parents are carriers of the defective Tay-Sachs gene, each child has a 25 percent chance of having Tay-Sachs disease and a 50 percent chance of being a carrier.
Can Tay-Sachs disease be detected before birth?
Before or during a pregnancy, couples can get screened for the Tay-Sachs gene with a simple blood test. If both carry the Tay-Sachs gene, a genetic counselor can provide more information. Pregnant women can have their unborn babies tested for Tay-Sachs disease through chorionic villus sampling (CVS) or amniocentesis.
How long is the average lifespan of a person with Tay-Sachs?
Tay-Sachs disease (TSD) is a genetic condition that affects the nervous system. It becomes progressively worse over time. Symptoms usually first appear at around six months of age in previously healthy babies. The life expectancy for children with TSD is around five years of age.
What are the chances of having Tay Sachs disease?
If both parents are carriers and their child inherits the defective Hex-A gene from each of them, the child will have Tay-Sachs disease. When both parents are carriers of the defective Tay-Sachs gene, each child has a 25 percent chance of having Tay-Sachs disease and a 50 percent chance of being a carrier.
Can a child be a carrier of Tay Sachs?
The child must receive two copies of the defective gene, one from each parent, in order to become sick. If only one parent passes the defective gene to the child, the child is called a carrier. They will not be sick, but may pass the disease to their own children. Anyone can be a carrier of Tay-Sachs.
How does Hex-a gene cause Tay Sachs disease?
Defect in Hex-A Gene Causes Tay-Sachs: Tay-Sachs disease results from defects in a gene on chromosome 15 that codes for production of the enzyme Hex-A. We all have two copies of this gene. If either or both Hex-A genes are active, the body produces enough of the enzyme to prevent the abnormal build-up of the GM2 ganglioside lipid.
What are the chances of inheriting an autosomal dominant disorder?
Autosomal dominant inheritance: A person affected by an autosomal dominant disorder has a 50 percent chance of passing the altered gene to each child. The chance that a child will not inherit the altered gene is also 50 percent.