NEPHROCALCINOSIS AND UROLITHIASIS IN CARBONIC-ANHYDRASE-II DEFICIENCYSYNDROME

We report three new Kuwaiti patients with carbonic anhydrase II defici ency (CA II) from two unrelated families. Each patient had osteopetros is, distal renal tubular acidosis, and cerebral calcification. Patient s from family 1 (a brother and a sister) had some facial anomalies and delayed development. At the age of 14 months, ultrasound studies in t he girl showed medullary nephrocalcinosis which has not been previousl y described in association with CA II, while cerebral CT scan revealed dilated ventricles. The patient from family 2, who had two previously reported affected siblings, developed bilateral recurrent renal stone s and hypercalciuria but no nephrocalcinosis. None of his affected sib lings had nephrocalcinosis or urolithiasis. DNA analysis of patients f rom both families showed that each of them was homozygous for the ''Ar abic'' mutation in the CA II gene. We report new features in three Ara b patients with CAII deficiency. Also review all previously reported C A II cases from Kuwait in order to highlight the inter-/intra-familial variability of the disease in this part of the world despite the over whelming prevalence of the same ''Arabic'' mutation among the patient population.