What Tay-Sachs Disease (TSD) is a neurological disease that autosomal recessive. If mother and father are both unaffected carriers for this gene what will be true of their offspring?

If both the mother and father are unaffected carriers for Tay-Sachs disease (TSD), each of them carries one copy of the defective gene responsible for the condition, while still having one functional copy. When they have children, the following possible combinations can occur in their offspring regarding TSD gene inheritance:

1. Unaffected (Non-carrier): 25% probability

- The child inherits two functional copies of the gene, one from each parent. The child is neither affected by the disease nor a carrier.

2. Carrier: 50% probability

- The child inherits one functional copy of the gene from one parent and one defective copy from the other parent. The child will not be affected by the disease but will be a carrier, meaning they can pass on the defective gene to their own children.

3. Affected (TSD): 25% probability

- The child inherits two defective copies of the gene, one from each parent. The child will be affected by Tay-Sachs disease.

This means that there is a 25% chance for each child of this couple to be affected by TSD, a 50% chance to be a carrier, and a 25% chance to be unaffected and non-carrier.