Hartnup Disease

**Definition:** An autosomal recessive disorder due to defective absorption of NEUTRAL AMINO ACIDS by both the intestine and the PROXIMAL RENAL TUBULES. The abnormal urinary loss of TRYPTOPHAN, a precursor of NIACIN, leads to a NICOTINAMIDE deficiency, PELLAGRA-like light-sensitive rash, CEREBELLAR ATAXIA, emotional instability, and aminoaciduria. Mutations involve the neurotransmitter transporter gene SLC6A19.

**Tree numbers:** - C10.228.140.163.100.355 - C12.050.351.968.419.815.885.625 - C12.200.777.419.815.885.457 - C12.950.419.815.885.625 - C16.320.565.151.355 - C16.320.565.189.355 - C16.320.831.885.457 - C18.452.132.100.355 - C18.452.648.151.355 - C18.452.648.189.355

**Synonyms:** - Transport Disorder, Neutral Amino Acid - Neutral Amino Acid Transport Defect - Transport Disorder, Neutral Amino Acids - Hartnup Disorder - Amino Acid Transport Disorder, Neutral - Neutral Amino Acid Transport Disorder