Tryptophanuria With Dwarfism

Tada et al. (1963) described a 9-year-old girl with dwarfism, mental defect, cutaneous photosensitivity, and gait disturbance resembling cerebellar ataxia. The clinical features resembled Hartnup disease (234500) but the chemical findings were different. Tryptophane was excreted in the urine in excess without increase in indican or indole acetic acid excretion. With tryptophane loading, the plasma level of tryptophane increased markedly and remained higher longer than in normals and tryptophanuria was increased with relatively little increase in kynurenine excretion. The defect was thought to concern the conversion of tryptophane to kynurenine. The disorder was thought to have occurred in 3 children (2 males and the female proband) in 3 sibships. All 6 parents were traced to a common ancestral couple. The proband showed conjunctival telangiectasia which together with ataxia creates similarities to ataxia-telangiectasia (208900).