What colour skin would the child of someone with albinism have?

Question

My question is assuming the baby doesn't have albinism. If the mother has albinism and her family all has dark skin and the father doesn't have albinism and has light skin, would the baby just get the father's skin colour, or would they get the gene for dark skin from the mother? Or if the mother would have dark hair if it weren't for her albinism, and the father has light hair, would it be possible for the baby to have dark hair? I guess another way to ask this question would be, does albinism cover up the genes that give you pigment, or does it cause you to not have those genes at all?

Answer 1

To answer the question we first have to take a look what albinism is and how it is caused.

Albinism is an inherited genetic condition that reduces the amount of melanin pigment formed in the skin, hair and/or eyes.It is characterized by the absence of pigment in the eyes, skin, hair, and other parts of the body. Albinism affects the production of melanin, which is responsible for coloring these areas. Symptoms may include vision problems and light sensitivity. See references 1 and 2 for more background information.

Mutations in several genes, including TYR, OCA2, TYRP1, and SLC45A2, are associated with albinism (references 3 and 4). These genes give instructions for making proteins involved in producing melanin, which is made by cells called melanocytes. Melanin is responsible for coloring the skin, hair and eyes. The most important gene is TYR (or tyrosinase) being resposible for the initial step in melanin biosynthesis.

Albinism is inherited in an autosomal recessive pattern, meaning a child must receive two copies of the gene that causes albinism (one from each parent) to have the condition. This means both parents must carry the gene for their child to be born with albinism. See reference 5.

To answer the question: If the mother has albinism, she has two non-functional copies of one of the genes mentioned above, otherwise she wouldn't be albinistic. If the father has two intact copies of the same gene, the kid will have normal pigmentation. However, as kids mixed from parents with a light and a strong pigmentation background it will most likely be darker than the father and lighter than his mother would be without albinism.

If the father carries a mutation on one allel of the genes which cause albinism for the mother and the other is normal, than there is a 50% chance that the kid is also albinistic.

References:

1. Information Bulletin – What is Albinism?
2. Albinism
3. Oculocutaneous albinism
4. Molecular basis of albinism: mutations and polymorphisms of pigmentation genes associated with albinism
5. Albinism

Answer 2

Skin color in humans is mainly determined by a pigment called Melanin. Melanin is produced by cells called melanocytes present in the epidermis of the skin. Melanin production rates are determined both by genetic and environmental factors. A high production of Melanin will result in what we call "dark skin color", and a low production will result in what we call "light skin color".

From the Wikipedia page for Albinism,

Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes.

This means that in an individual with Albinism, Melanin production is extremely low.

Albinism is usually caused by genetic mutations to some of the hundreds of genes that affect Melanin production. As Wikipedia quotes,

All the genetic traits for albinism are recessive traits. This means that their influence is hidden when paired with stronger traits. For the recessive albino trait to be expressed in a mammal, the offspring must inherit a recessive gene from both parents.

You ask about a baby getting the gene for dark skin color from an albino mother. What's important in understanding here is that the mother doesn't have a gene for dark skin color. Albinism is caused by mutations to genes, so an albino's genes encode for albinism, meaning they don't have any genes for "dark" or "light" skin color.

Albinism is recessive, meaning that an individual with only one copy of a gene for albinism will not exhibit albinism. So if the father of the baby in the situation you mention does not have a hidden gene for albinism, the baby will likely exhibit the father's skin color. The same is true if the father has a hidden gene for albinism, but doesn't give this gene to the baby. If the father passes on a gene for albinism to the baby, however, the baby will likely be an albino, considering the recessive allele it receives from both parents.