Tay Sachs disease is caused by a recessive mutation on chromosome 15,and 1 of every 27 members of the Old Order Amish community of Pennsylvania carry a recessive allele.What is the chance that an Old Order Amish man who carries the allele will have a child with Tay Sachs? (Remember,the community restricts marriage to other members of the community. )

Question

Quizplus · Accepted Answer

Since the man is a carrier (with one recessive allele), the chance that his partner is also a carrier is 1/27 (given for the community). For their child to have Tay Sachs, both parents must pass on the recessive allele. The chance of each parent passing on the allele is 1/2, so the combined chance is 1/2 * 1/2 = 1/4. Therefore, the overall probability is 1/27 (chance the partner is a carrier) * 1/4 (chance both pass on the allele) = 1/108, which is approximately 0.926%.

Tay Sachs Disease Is Caused by a Recessive Mutation on Chromosome