Achondroplasia
a. affects only homozygotes
b. is inherited as an x-linked disorder
c. is inherited as an autosomal recessive condition
d. is characterized by abnormally short arms and legs
e. affects about one in one million people

Achondroplasia is a genetic disorder that cause people to have shorter bone, thus having short arms and legs. The disease is caused by mutation in FGFR3 and inherited as autosomal dominant. Homozygotes will have a lethal allel and died short time after birth.

4, two dominant and two recessive