Determine4 marksStandard
Albinism in humans is caused by a recessive allele of the TYR gene, which codes for the enzyme tyrosinase. Individuals with two copies of the recessive allele lack functional tyrosinase and have albinism. The dominant allele T produces normal tyrosinase activity.
A man and a woman both have normal pigmentation. Their first child has albinism.
Determine the genotypes of the parents and the probability that their next child will also have albinism. Show your working using a genetic diagram.