Tay-Sachs is a recessive lethal disease in which there is neurological deterioration early in life. This disease is rare in the population overall but is found at relatively high frequency in Ashkenazi Jews from Central Europe. A woman (Mary) whose maternal uncle had the disease is trying to determine the probability that she and her husband could have an affected child. Her father does not come from a high-risk population. Her husband’s sister died of the disease at an early age. Show your work.

1) Assume Mary’s mother is a carrier. Use the product or sum rule (whichever is appropriate ) to determine the probability that the Mary is a carrier for the Tay-Sachs disease allele. Write out your logic.
2) Determine the probability that Mary’s first child will be affected. Show your work.