What Causes Albinism?
Albinism is primarily caused by mutations in the genes responsible for producing or distributing melanin, the pigment that gives color to the skin, eyes, and hair. In people with albinism, these mutations result in little to no melanin production, which leads to the characteristic pale appearance of the skin, hair, and eyes. Melanin is crucial not only for pigmentation but also for protecting the skin and eyes from harmful UV radiation. Without sufficient melanin, individuals with albinism face heightened risks of skin damage from the sun and vision impairment.
The genetic mutations that lead to albinism are generally inherited from both parents, with each parent carrying a defective gene. The inheritance pattern follows an autosomal recessive model, meaning both copies of the gene (one from each parent) need to carry the mutation for the condition to manifest. If only one parent carries the mutated gene, the child will be a carrier and won’t show symptoms, but they can pass the gene onto future generations.
Inheritance Patterns of Albinism
Albinism follows an autosomal recessive inheritance pattern. This means that for an individual to be born with albinism, both parents must carry at least one copy of the defective gene, even if they do not show signs of the condition themselves. When both parents are carriers of the albinism gene mutation, each child has a 25% chance of inheriting two mutated copies of the gene and, therefore, developing albinism.
In cases where only one parent carries the gene, the child may inherit one copy of the mutated gene and one normal gene, making them a carrier, but they won’t have the condition. This is why albinism is relatively rare — the condition requires both parents to be carriers or to have the condition themselves.
Genetic Testing and Diagnosis of Albinism
Genetic testing plays a critical role in diagnosing albinism, especially in infants and young children. This test looks for specific mutations in the genes associated with melanin production. Since the symptoms of albinism, such as pale skin and vision problems, can resemble other conditions, genetic testing is often used to confirm a diagnosis.