Albinism is due to:
**Core Concept**
Albinism is a group of rare genetic disorders characterized by the complete or partial deficiency of melanin production, leading to a lack of pigmentation in the skin, hair, and eyes. This condition is caused by mutations in genes involved in melanin synthesis, affecting the production of eumelanin and pheomelanin.
**Why the Correct Answer is Right**
The correct answer is related to the enzyme tyrosinase, which is a key enzyme in the melanin synthesis pathway. Tyrosinase catalyzes the conversion of tyrosine to L-DOPA, a crucial step in the production of eumelanin. Mutations in the TYR gene, which encodes tyrosinase, can lead to a complete or partial loss of enzyme activity, resulting in albinism. This is because tyrosinase is essential for the initiation of melanin synthesis, and its absence or reduced activity prevents melanin production.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct enzyme involved in melanin synthesis. While other enzymes, such as DOPAchrome tautomerase, are involved in melanin production, tyrosinase is the primary enzyme responsible for initiating melanin synthesis.
**Option B:** This option is incorrect because it is not a specific enzyme involved in melanin synthesis. While it is related to the melanin pathway, it is not the correct answer.
**Option C:** This option is incorrect because it is not a gene or enzyme directly involved in melanin synthesis. While it may be related to other aspects of melanin biology, it is not the correct answer.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that albinism is a rare genetic disorder, and its diagnosis is often based on clinical examination, patient history, and genetic testing. A thorough understanding of the melanin synthesis pathway and the role of tyrosinase in this process is crucial for diagnosing and managing patients with albinism.
**Correct Answer: C. Tyrosinase deficiency**