CQ3 Huntington disease is a late-onset disease caused by a single, autosomal dom
ID: 3164530 • Letter: C
Question
CQ3 Huntington disease is a late-onset disease caused by a single, autosomal dominant mutation. The following pedigree is for a family with a history of Huntington disease Those individuals who are already suffering from the disease are shaded black. However, some additional individuals in Huntington allele and will develop Huntington disease but have not yet shown symptoms. Assume that individuals marrying into the family have no history of Huntington disease (that is, they are homozygous recessive for the gene). Also assume that the diseased male in generation I is heterozygous for the disease gene. rat ions II and III also carry the a b c de ghij k m a. If individuals IIIg and Ila had a child together, what is the probability that the child would develop Huntington disease? A. 1/4 ?. 1/6 C. 1/2 D. 1/8 E. 1/3Explanation / Answer
CQ3) D - 1/8 (1/2X1/4) {Probbilty of IIIG gamete has Huntington disease allele X Probability of IIa's gamete having Huntington disease allele}
CQ4) A - 1/4 (1/2X1/2)
CQ5) C - 1/2 (1X1/2)