Chapter 5, Problem 14P

$\text{Nail–patella}$ syndrome is an autosomal disorder affecting the shape of nails on fingers and toes as well as the structure of kneecaps. The pedigree below shows the transmission of

$\text{nail–patella}$ syndrome in a family along with ABO blood type.

a. Is $\text{nail–patella}$ syndrome a dominant or a recessivecondition? Explain your reasoning.

b. Does this family give evidence of genetic linkage between $\text{nail–patella}$ syndrome and ABO blood group? Why or why not?

c. Using N and n to represent alleles at the $\text{nail–patella}$ locus and $\text{I A, I B,}$ and $\text{ i}$ to represent ABO alleles, write thegenotypes of $\text{I-1}$ and $\text{I-2}$ as well as their five children in generation $\text{II}$.

d. Explain why $\text{III-6}$ has $\text{nail–patella}$ syndrome and $\text{III-8}$ does not. Give genotypes for these two individuals.

e. Explain why $\text{III-11}$ has $\text{nail–patella}$ syndrome and $\text{III-12}$ does not. Give genotypes for these two individuals.