Specific for albinism-
## Core Concept
Albinism refers to a group of rare genetic disorders that cause the skin, hair, and eyes to have little to no color. The condition is primarily related to defects in the production of melanin, which is produced by cells called melanocytes. There are several types of albinism, with the most common being oculocutaneous albinism.
## Why the Correct Answer is Right
The correct answer involves understanding the genetic basis of albinism. Albinism is often inherited in an autosomal recessive pattern, meaning that a person must inherit two defective genes (one from each parent) to express the condition. The genes involved in albinism encode for proteins crucial in the melanin production pathway. One of the key genes associated with albinism is the **TYR** gene, which encodes for the enzyme tyrosinase. This enzyme is essential for converting the amino acid tyrosine into melanin. Mutations in the **TYR** gene lead to tyrosinase-deficient albinism, a severe form of oculocutaneous albinism.
## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it does not specify a gene or a condition directly linked to albinism.
- **Option B:** This option is incorrect as it does not directly relate to a known genetic cause of albinism.
- **Option D:** This option is incorrect because it does not accurately represent a specific genetic defect associated with albinism.
## Clinical Pearl / High-Yield Fact
A key clinical pearl is that individuals with albinism often have **visual impairments**, including photophobia, nystagmus, and significantly reduced visual acuity, in addition to their lack of pigmentation. This is due to the abnormal development of the retina and the optic nerve during fetal development.
## Correct Answer Line
**Correct Answer: C.**