CLINICAL AND MOLECULAR HETEROGENEITY IN CARBONIC-ANHYDRASE-II DEFICIENCY AND PRENATAL-DIAGNOSIS IN AN ITALIAN FAMILY

Carbonic anhydrase (CA) II deficiency is characterized by osteopetrosi s, renal tubular acidosis, cerebral calcification, and usually severe mental retardation. We describe an Italian boy with this disease whose mental retardation was relatively mild and whose renal tubular acidos is had only a distal component. A novel mutation of a gt - > tt change of splice donor site at the 5' end of intron 6 was demonstrated. Comp arison of this patient with two previous Italian families with differe nt mutations illustrates the clinical and molecular heterogeneity of t his disease. The identification of the mutation in this family provide d the opportunity for prenatal diagnosis in a subsequent pregnancy.