Gyrate atrophy of retina is caused by accumulation of:
**Core Concept**
Gyrate atrophy of the retina is a rare, inherited condition characterized by progressive loss of vision. It is caused by mutations in the **ornithine aminotransferase (OAT)** gene, leading to deficiency of the OAT enzyme. This deficiency results in elevated levels of **ornithine** in the blood.
**Why the Correct Answer is Right**
The correct answer is related to the biochemical pathway involving **ornithine**. In gyrate atrophy, the deficiency of **ornithine aminotransferase** leads to an accumulation of **ornithine**, which is toxic to the retina. This accumulation causes progressive damage to the retinal cells, resulting in vision loss.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not directly related to the **ornithine aminotransferase** deficiency.
**Option B:** Incorrect as it does not accumulate due to **ornithine aminotransferase** deficiency.
**Option C:** Incorrect because it is not the primary accumulating substance in gyrate atrophy.
**Clinical Pearl / High-Yield Fact**
Gyrate atrophy is an autosomal recessive disorder, and its diagnosis is crucial for genetic counseling. The key to diagnosis is the measurement of **ornithine** levels in the blood and mutation analysis of the **OAT** gene.
**Correct Answer:** D. Ornithine