Albinism results from genetic variations (mutations) in DNA that affect the production of melanin, the pigment responsible for skin, hair, and eye color.
Here's a breakdown of what happens to DNA in individuals with albinism:
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Gene Mutations: Albinism is primarily caused by mutations in genes involved in melanin production. These genes contain the instructions for creating proteins that are essential for melanogenesis (the process of melanin synthesis). The TYR gene is most commonly affected, but other genes such as OCA2, TYRP1, and SLC45A2 can also be involved.
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Disrupted Melanin Production: The mutations in these genes disrupt or completely prevent the proper functioning of the proteins required for melanin production. This can lead to a significant reduction or absence of melanin in the skin, hair, and eyes.
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Recessive Inheritance: Albinism is often inherited in an autosomal recessive pattern. This means that a person must inherit two copies of the mutated gene (one from each parent) to have albinism. Individuals who inherit only one copy of the mutated gene are carriers and typically do not exhibit symptoms of albinism.
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DNA Sequencing and Diagnosis: DNA sequencing can be used to identify the specific gene mutations that cause albinism in affected individuals. This can help in confirming the diagnosis and providing genetic counseling to families.
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No Direct Structural Changes to DNA: The DNA itself doesn't undergo any drastic structural change, such as deletion or rearrangement of large sections, in albinism. Instead, the problem arises from specific point mutations, insertions, or deletions within the genes that control melanin production. These subtle changes alter the way the genetic code is read and translated into functional proteins.
In summary, albinism is caused by mutations in DNA that code for proteins crucial for melanin production. These mutations disrupt or prevent the production of melanin, resulting in reduced or absent pigmentation. The inheritance pattern is commonly autosomal recessive.
