An update on the frequency of nonclassic deficiency of adrenal 21-hydroxylase in the Yugoslav population

Nonclassic steroid 21-hydroxylase deficiency is an attentuated adrenal enzyme defect that is commonly the basis of hyperandrogenic syndromes. Inherited as an autosomal recessive trait, it is known to occur with high frequency in the general population and with increased frequency in a number of ethnic groups, including the Yugoslav population. Following expansion of the original data on 21 families in Croatia to a total of 49 Croatian and Serbian families, we establish that this enzymatic disorder is increased in this Slavic population and provide an updated estimate for the gene frequency of 0.092 (0.035-0.149). Also in keeping with earlier reports, we continue to note the absence of association between nonclassic 21-hydroxylase deficiency occurring among Yugoslavs and HLA-B14; DR1.