Primary, vitamin B6-dependent cystathioninuria occurred in a mentally retarded adolescent who had juvenile diabetes mellitus. The patient was homozygous for this disorder, and his parents were heterozygous. No other instance of concurrence of these two diseases was noted on examination of the urine of a small series of 12 patients with diabetes mellitus. This report cites another metabolic abnormality accompanying cystathioninuria. Patients with endocrine disorders and alterations in intellectual development should be screened for this metabolic abnormality.
AvRuskin TW, Kang ES. Cystathioninuria, Mental Retardation, and Juvenile Diabetes Mellitus. Am J Dis Child. 1974;127(2):250-253. doi:10.1001/archpedi.1974.02110210100015