Can marriage between two albinos produce children with normal pigmentation?

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Albinism is a genetic condition where a person lacks melanin, the pigment responsible for the colour of skin, hair and eyes. It is usually inherited in an autosomal recessive manner. The most common forms of albinism, such as oculocutaneous albinism (OCA), are caused by mutations in genes like TYR, OCA2, TYRP1 etc. For a person to show albinism, they must inherit two copies of the defective allele, one from each parent. This means the genotype of an albino individual is generally homozygous recessive (aa).

If both parents are albino due to mutations in the same gene, then their genotype would be aa, and the only gametes they can produce will carry the a allele. When we perform a cross:

Parent 1: aa × Parent 2: aa

Gametes: a a

All children will also be aa, hence all children will be albino. Therefore, if both parents are albino due to the same gene, they cannot produce a normally pigmented child.

However, in rare cases, albinism can result from mutations in different genes in each parent. For example, one parent may be albino due to a mutation in the TYR gene (genotype aaBB) and the other due to a mutation in the OCA2 gene (genotype AAbb). In this case, each child will inherit one normal allele for both genes, resulting in AaBb genotype. Since both A and B alleles are dominant, melanin production will be normal and the child will show normal pigmentation. This phenomenon is known as genetic complementation.

So, marriage between two albinos can rarely produce normally pigmented children, but only if the mutations causing albinism are in different genes. If the mutations are in the same gene, then all children will be albino.

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