title: Mineralocorticoid unresponsiveness with severe neonatal hyponatremia and hyperkalemia.
abstract: An infant with severe neonatal hyponatremia and hyperkalemia is described. Although marked elevations of urinary 17-hydroxycorticosteroids suggested an 18-dehydrogenase aldosterone biosynthetic defect, the infant proved to have mineralocorticoid unresponsiveness, or pseudohypoaldosteronism. Dietary sodium supplementation and ion exchange resin administration resulted in normalization of serum electrolytes and urinary 17-hydroxycorticosteroids. ACTH infusion produced natriuresis, suggesting the need for additional sodium supplementation during the stress of illness, with a resultant increase in ACTH secretion. Determinations of the relative amounts of urinary 18-hydroxy and aldosterone metabolites appear necessary for early definitive diagnosis of the disorder.
mesh_terms: D015065:17-Hydroxycorticosteroids / Q000652:urine*; D000324:Adrenocorticotropic Hormone; D000450:Aldosterone / Q000652:urine; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000378:metabolism* / Q000628:therapy; D007010:Hyponatremia / Q000378:metabolism* / Q000628:therapy; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000378:metabolism* / Q000628:therapy; D008901:Mineralocorticoids / Q000652:urine*; D011188:Potassium / Q000097:blood / Q000652:urine; D012964:Sodium / Q000097:blood / Q000652:urine
chemical_list: D015065:17-Hydroxycorticosteroids; D008901:Mineralocorticoids; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D012964:Sodium; D011188:Potassium