Question

Parents are carrier for albinism. What will be the genotype of first three children?

• A. Some normal, heterozygous and albino
• B. All normal
• C. All heterozygous albino
• D. All albino

Answer 1

Answer: (A)

Some normal, heterozygous and albino

Albinism is an autosomal recessive disorder which means that only homozygous recessive genotype will show the disorder. The heterozygous genotype will be normal but will serve as a carrier since the recessive gene is masked by the presence of the normal dominant gene. According to the question, both parents are a carrier (heterozygous normal).
Parent generation: Aa (carrier mother) X Aa (carrier father)

Gametes : Aa $\to$ $\downarrow$	A	a
A	AA (normal child)	Aa (normal carrier child)
a	Aa (normal carrier child)	aa (albino child)

F${}_1$ generation = 1 normal child: 2 normal carrier child: 1 albino. Hence, the first three children can be normal, heterozygous and albino; option A is the correct answer.