Familial hypertryptophanemia in two siblings.

Mild and moderate mental retardation with exaggerated affective responses, periodic mood swings, and apparent hypersexual behavior were present in two siblings with hypertryptophanemia and tryptophanuria. In addition, the male had severe myopia, a speech impediment, musculoskeletal abnormalities and perceptual hypersensitivity. His sister was deaf, which was ascribed to antenatal rubella. The occurrence in siblings and the presence of abnormal urinary tryptophan metabolite in the mother and a half-sibling suggest that the condition results from an autosomal recessive gene with minor expression in some heterozygotes.