Use

This test aids in the screening and monitoring of Hartnup disease by measuring urinary tryptophan, an essential amino acid, which is metabolically critical for synthesis of serotonin, melatonin, and niacin. Hartnup disease is an autosomal recessive disorder characterized by impaired neutral amino acid transport, leading to increased renal excretion of tryptophan and potential niacin deficiency, resulting clinically in pellagra-like rash and neurological symptoms such as ataxia. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/Overview/83823?utm_source=openai))