Prolinuria: defect in intestinal absorption of imino acids and glycine.

T.K., a female, was born after full term and spontaneous delivery, weighing 2,260 g. Her parents were healthy and not consanguineous. There was no sibling. The patient was breast fed and appeared to be healthy until 6 months of age, when the parents wondered if she might be mentally retarded. Even beyond one year of age she could neither stand nor sit alone. There was no history of convulsions or severe illness. On admission at the age of 15 months, physical examination revealed a moderately nourished girl with a habit of finger sucking. Her weight, height and circumference of the head were found to be within normal limits. Extremities were flaccid, and she could neither stand nor sit up. She could hold up her head steadily. She was able to follow the light and to react to auditory or painful stimuli. The liver was softly palpable one fingerbreadth under the costal margin. The spleen was not palpable. Funduscopic examination revealed no abnormalities. There were no neurologic abnormalities otherwise. Laboratory findings: Routine blood studies and determination of chemical con stituents in serum, including protein and its electrophoretic pattern, electrolytes, lipids, nonprotein nitrogen and creatinine, were within normal limits. Liver function tests gave normal results. X-ray films of the skull, chest and extremities revealed no pathologic findings. Intravenous pyelography indicated no abnormalities. Histologic findings of the biopsied kidney was found to be normal (cf. Fig. 1). Electroencephalogram revealed hypsarhythmia. Routine urinalysis gave no abnormalities. The thin-layer chromatography of urinary