Follow-up studies on children with severe dietary chloride deficiency during infancy.

Ten children who had severe dietary chloride deficiency during early infancy have grown normally during their first 4 to 5 years. With the exception of one child who did not get into the sitting position alone until he was 9 1/2 months of age, the patients reached the usual developmental milestones of the first 2 years during the expected age intervals. Developmental and psychological testing indicates that all of the children have at least average ability. However, three children have shown behavior patterns that may interfere with successful school performance. Serum creatinine and urea nitrogen concentrations appear to be normal as does renal concentrating capacity. During a 4-year follow-up, one child has shown persistent and a second intermittent microscopic hematuria.