Case Workbook for Human Genetics 9th Edition by Ricki Lewis

Exercise 5

Thiamine-responsive megaloblastic anemia is a rare autosomal recessive condition that causes anemia, diabetes mellitus, and hearing loss. It is treatable with high doses of thiamine.
a.Which individuals in the pedigree below must be carriers?
b.What is the special relationship that led to the illness in two members of the fourth generation?