Gyrate atrophy is a retinal degenerative disease involving deficiency of ornithine transcarbamoylase enzyme. Such patients are benefited by
**Core Concept**
Gyrate atrophy is a rare autosomal recessive disorder affecting the retina. It is characterized by a deficiency of ornithine transcarbamoylase (OTC) enzyme, which is involved in the urea cycle. The urea cycle is crucial for the detoxification of ammonia, a neurotoxic compound produced during protein catabolism.
**Why the Correct Answer is Right:**
Patients with gyrate atrophy suffer from hyperammonemia due to the impaired detoxification of ammonia. Administration of L-ornithine, the precursor of OTC, can help in compensating the deficiency and reducing ammonia levels. Option A refers to L-ornithine, which is a suitable treatment for gyrate atrophy, as it can bypass the deficient OTC enzyme and support ammonia detoxification.
**Why Each Wrong Option is Incorrect:**
Option B (L-arginine) is incorrect because it is not a precursor to OTC enzyme and doesn't directly help in the urea cycle. Option C (L-citrulline) is incorrect as it is not a direct precursor to OTC, although it is involved in the urea cycle. Option D (L-alanine) is not related to urea cycle or OTC enzyme activity.
**Why Each Wrong Option is Incorrect:**
Option B (L-arginine) is incorrect because it is not a precursor to OTC enzyme and doesn't directly help in ammonia detoxification. Option C (L-citrulline) is incorrect as it is involved in the urea cycle but not a direct precursor to OTC enzyme, although it is involved in urea cycle. Option D (L-alanine) is not related to urea cycle or OTC enzyme activity.
**Clinical Pearl:**
Gyrate atrophy patients require lifelong supplementation of L-ornithine to maintain ammonia homeostasis and prevent neurological complications. This highlights the importance of understanding the role of specific amino acids in the urea cycle and their contribution to ammonia detoxification.
**Correct Answer:**
Correct Answer: L-ornithine