Eric and Janelle are carriers of the recessive allele causing Tay-Sachs disease, which is lethal in early childhood. If they have a healthy child, what is the probability that this healthy child would NOT be a carrier of Tay-Sachs disease?

75% probability that the child will not be a carrier.

Explanation: The Tay-Sachs disease is caused by mutation of the HEXA gene.

Tay–Sachs disease is an autosomal recessive genetic disorder, meaning that when both parents are carriers, there is a 25% risk of giving birth to an affected child with each pregnancy. A mutated copy of the gene is passed from each parent to the affected child. The causes are Genetic.