Part A If this disease is caused by a rare recessive allele of an autosomal gene
ID: 168929 • Letter: P
Question
Part A
If this disease is caused by a rare recessive allele of an autosomal gene, what is the probability that the second child of A & B will have the disease?
Enter your answer as a single probability from 0 to 1.
Part B
If this disease is caused by a common recessive allele of an X-linked gene, what is the probability that the first daughter of A & B would have the disease?
Enter your answer as a single probability from 0 to 1.
IV Consider this human pedigree for a disease caused by a single geneExplanation / Answer
Part A
If this disease is caused by a rare recessive allele of an autosomal gene, what is the probability that the second child of A & B will have the disease?
Enter your answer as a single probability from 0 to 1.
II-2, II-3 and II-4 are 100% carriers of this autosomal allele
III-2 is a ½ chance of being a carrier
III-3 is chance of being a carrier
IV-A is ½ x ½ = ¼ chance of being a carrier
IV-B is x ½ = chance of being a carrier
The probability of second child being affected is = ¼ x x = 1/36 = 0.027