A man who is a known heterozygous carrier of oculocutaneous albinism marries his half-cousin (they share one common grandparent) as shown in the pedigree below. This trait is transmitted as a fully penetrant autosomal recessive. What is the probability that this couple will produce a child with this disorder?
A. 1/2 B. 1/4 C. 1/8 D. 1/16 E. 1/64
My calculation was 1/2 (for II-2 as he must be carrier) * 1/2 (for II-3) * 1/2 (for III-2) * 1/4 = 1/32. Please help me out by proper explanation to your steps and point out my mistakes. The correct answer given is 1/64. Pedigree shown in the image below.