Neonatal primary hyperparathyroidism in familial hypocalciuric hypercalcemia.

A Japanese female neonate exhibiting severe respiratory distress was found to have primary hyperparathyroidism. Features included demineralization of the bones, hypercalcemia, hypophosphatemia, and elevated levels of parathyroid hormone, together with marked, generalized aminoaciduria. Four enlarged parathyroid glands were surgically removed, and remineralization of the bones was noticed after the operation. The characteristic pathologic change of the glands was chief cell hyperplasia. A survey of the family identified three other hypercalcemic but asymptomatic relatives. The mode of inheritance was autosomal dominant. This patient seems to be the second neonate with familial hypocalciuric hypercalcemia to be described in the literature.