Question

Imagine a genetic counselor working with a couple who have just had a child who is suffering from Tay-Sachs disease. Neither parent has Tay-Sachs, nor does anyone in their families. Which of the following statements should this counselor make to this couple?A. "Because no one in either of your families has Tay-Sachs, you are not likely to have another baby with Tay-Sachs. You can safely have another child."
B. "Because you have had one child with Tay-Sachs, you must each carry the allele. Any child you have has a 50% chance of having the disease."
C. "Because you have had one child with Tay-Sachs, you must each carry the allele. Any child you have has a 25% chance of having the disease."
D. "Because you have had one child with Tay-Sachs, you must both carry the allele. However, since the chance of having an affected child is 25%, you may safely have thee more children without worrying about having another child with Tay-Sachs."
E. "You must both be tested to see who is a carrier of the Tay-Sachs allele."

Answer 1

Answer: The correct answer to the question is option C

BECAUSE YOU HAVE HAD ONE CHILD WITH TAY-SACHS,YOU MUST EACH CARRY THE ALLELE.ANY CHILD YOU HAVE HAS A 25% CHANCE OF HAVING THE DISEASE.

Explanation: Tay- Sachs is a rare disorder that is inherited,it is characterised by a progressive destruction of the nerves of the brain and spinal cord.its onset is from around 6months of life to around 4-5years of age when the child affected eventually dies.

A Child that have Tay-Sachs experiences problem with coordination,muscle contraction, must stiffness and weakness.there is also difficulty is speaking, swallowing, wasting(uncontrolled weightloss), hearing loss,seizure, and vision loss.

Since the parents of the child in the question claims they don't have Tay- Sachs and no one in the family has it but they came down with a child having Tay-Sachs and one of the major factors to Tay-Sachs as stated above is heredity,the main point to counsel the couples on is that because they have had one child with Tay-Sachs,they most each carry the allele which is obviously recessive so any child they had have has 25% chance of having the disease.