Hypercalcemia and nephrocalcinosis in patients with congenital lactase deficiency.
We describe 11 infants with congenital lactase deficiency, whose age at diagnosis varied from 6 to 88 days. At the time of admission, 7 of 10 infants had hypercalcemia. Five of the seven infants for whom renal ultrasonography was performed at the time of diagnosis had medullary nephrocalcinosis. Hypercalcemia ceased within a week of the start of a lactose-free diet. At the time of reevaluation, at the ages of 2 to 10 years, one of the patients still had hypercalciuria and nephrocalcinosis was still present in 3 of 11 patients. The mechanism of hypercalcemia is unclear but may be related to metabolic acidosis or may be promoted by the lactose effect (i.e., by nonhydrolyzed lactose that has a direct enhancing effect on calcium absorption in the ileum).
Saarela
T
T
Department of Pediatrics, University of Oulu, Finland.
Similä
S
S
Koivisto
M
M
D000138:Acidosis; D002114:Calcinosis / Q000150:complications* / Q000175:diagnosis / Q000473:pathology; D002118:Calcium / Q000097:blood; D002648:Child; D002675:Child, Preschool; D006801:Humans; D006934:Hypercalcemia / Q000150:complications* / Q000175:diagnosis; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000473:pathology; D001616:beta-Galactosidase / Q000172:deficiency*
D001616:beta-Galactosidase; D002118:Calcium