Transient congenital hypoparathyroidism: possible association with anomalies of the pulmonary valve.

Transient congenital hypoparathyroidism was observed in four neonates who also had congenital cardiac defects. Severe hypocalcemia and hyperphosphatemia were noted at 2 or 3 weeks of age, but resolved by 2 to 4 months of age with minimal treatment (oral calcium alone). Parathyroid hormone, measured with a highly sensitive, homologous antiserum, was initially borderline detectable and became easily detectable as the hypocalcemia resolved. Immune function was normal in each patient. The congenital cardiac defects in each case involved the pulmonary valve. These patients might be regarded as having either a partial form of the DiGeorge syndrome or a separate syndrome in which congenital pulmonary valve lesions are linked to delayed maturation of parathyroid function by an as yet obscure mechanism.