DISTRIBUTION OF HEMOGLOBINOPATHY VARIANTS BY ETHNICITY IN A MULTIETHNIC STATE

It has been well known for many years that Black Americans are at incr eased risk for sickle cell disease and that individuals of Mediterrane an ancestry are at increased risk for thalassemias. Beyond this, howev er, complete assessments of the epidemiology of hemoglobinopathies in Americans have been constrained by lack of large enough sample size, i ncomplete diagnostic work or testing inadequacies, or missing or misle ading ethnicity data. California began universal, mandatory screening of all infants born in the state in 1990, and by January 1996, had scr eened over 3.3 million infants of various ethnic backgrounds. New info rmation is now available on groups at increased risk for disease, as w ell as carrier status. The overall prevalence of sickle cell disease ( all types) remains high in Blacks at 1 per 396 births, but is lower th an expected (from east coast/Caribbean published data) for Hispanics a t 1 in 36,000 births or from previously published data on other higher risk groups such as Middle Eastern (no cases in over 22,000 screens) or Asian Indian (1 case in 16,000 screens). The distribution of differ ent types of sickle cell disease has also changed, with increased numb ers of Hb SE disease resulting from multiethnic partnerships. Demograp hic trends in California have led to a major sift in the at-risk group s for major beta thalassemias, with the majority of cases detected in families of Asian, Southeast Asian, and Asian Indian ancestry. The ''n ew'' hemoglobinopathy condition in California, Hb E/Beta Thalassemia, is found almost exclusively in Southeast Asians with a prevalence of 1 in every 2,600 births. Carrier conditions are found in virtually ever y ethnic category, with higher than expected rates in non-Hispanic Whi tes (1 per 600 births). (C) 1996 Wiley-Liss, Inc.