Hartnup disease is a type of renal aminoaciduria characterised by selective failure of tubular reabsorption of a number of monoamino-monocarboxylic acids such as tryptophan. Deficiency of tryptophan produces pellagra-like symptoms which are accentuated by poor diet. Cerebellar ataxia and a mild mental handicap may be present.
In tandem with the renal deficiency, there is a failure to absorb neutral amino acids from the gut.
This condition is inherited as an autosomal recessive disease.
Treatment is with vitamins from the B complex and nicotinamide.