Albinism is most commonly caused by mutations in the TYR gene, also known as the P gene, located on chromosome 15.
Understanding the TYR Gene and Albinism
The TYR gene provides instructions for making an enzyme called tyrosinase. This enzyme is crucial for the production of melanin, the pigment responsible for skin, hair, and eye color. Mutations in the TYR gene lead to a deficiency or complete absence of tyrosinase, resulting in a significant reduction or absence of melanin. This is the hallmark of albinism.
Different types of albinism exist, each caused by mutations in various genes related to melanin production. However, the most common form is linked to the TYR gene.
Types of Albinism and Associated Genes
While the TYR gene is the most frequent culprit, it's important to note that other genes can also be involved in different forms of albinism. These include:
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OCA2 gene: This gene is involved in another type of albinism. Mutations here also disrupt melanin production, leading to similar symptoms as TYR-related albinism but often with different symptom severity.
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Other Genes: Several other, less common genes involved in the melanin pathway can also cause albinism when mutated.
Impact of TYR Gene Mutations
Mutations in the TYR gene can lead to a range of albinism severity. Some individuals may have mild symptoms, while others experience significant vision impairment and increased sun sensitivity.
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Complete Absence of Melanin: Some mutations completely disable the tyrosinase enzyme, leading to a complete lack of melanin.
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Reduced Melanin Production: Other mutations may lead to a reduced amount of functional tyrosinase, resulting in reduced melanin production.
Understanding the specific gene mutation involved in an individual's albinism allows for better diagnosis, management, and genetic counseling.
