Impaired Distal Tubular Acidification, Renal Cysts and Nephrocalcinosis in Monogenic Hypertension

Monogenic defects in tubular sodium handling contribute a small proportion to hypertension in childhood. Presentation varies from severe hypertension manifesting at birth to asymptomatic hypertension and hypokalemic metabolic alkalosis detected incidentally in adulthood. A 12-y-old girl presenting with polyuria, polydipsia, severe hypertension and seizures, was found to have hypokalemia, renal medullary cysts and nephrocalcinosis. Clinical exome revealed a homozygous variation of unknown significance in exon 5 of the HSD11B2 gene, indicating the diagnosis of apparent mineralocorticoid excess. Therapy with spironolactone was associated with resolution of hypokalemia and normal blood pressure during two-year follow up.