Question

In the following pedigree, a rare single gene disease is transmitted. What is the chance that individual IV-1 would be affected? First determine the mode of inheritance of the disease.

a) Autosomal dominant
b) Autosomal recessive
c) X-linked dominant
d) X-linked recessive

Answer 1

The mode of inheritance for the rare single gene disease in the pedigree is autosomal recessive. It is not possible to determine the exact chance that individual IV-1 would be affected without additional information. Hence the correct answer is option B

Step-by-step explanation:

Based on the given information, the mode of inheritance for the rare single gene disease in the pedigree is autosomal recessive. In autosomal recessive inheritance, the disorder corresponds to the recessive phenotype, and affected individuals are usually homozygous recessive. To determine the chance that individual IV-1 would be affected, we need to look at the parents' genotypes. If both parents are carriers (heterozygous), there is a 25% chance that their child will be affected. However, without additional information about the genotypes of the parents, it is not possible to calculate the exact chance for individual IV-1 to be affected.

Hence the correct answer is option B