Hartnup Disease Underlying Cause
Aminoaciduria is an inherited disorder. The kidneys release abnormally large amounts of one type of amino acid into the urine.
Types of aminoacidurias include:
Hartnup Disease Cystinuria
Hartnup Disease Hartnup Disease
Hartnup disease is an inherited aminoaciduria. It results in the accumulation of amino acid, tryptophan, in the urine. This occurs due to defective intestinal absorption of tryptophan.
It is characterized by a skin rash and difficulties with balance and incoordination.
Hartnup Disease Homocystinuria
Homocystinuria results in the accumulation of amino acid, methionine, in the urine.
- Dislocation of the lens of the eye
- Tendency to form blood clots in the arteries and veins
- Psychiatric problems
- Skeletal abnormalities
Newborns may have:
- Failure to thrive
- Mental retardation
- Chest and skeletal abnormalities
Hartnup Disease Phenylketonuria
- Brodehl J, Bickel H. Aminoaciduria and hyperaminoaciduria in childhood. Clin Nephrol. 1973 May-Jun;1(3):149-68. 
- Buehler BA. Inherited disorders of amino acid transport in relation to the kidney. Ann Clin Lab Sci. 1981 May-Jun;11(3):274-8. 
- Ozand PT, Gascon GG. Organic acidurias: aPart 2. J Child Neurol. 1991 Oct;6(4):288-303.