Prevalence and geographic distribution of abnormal hemoglobins in the state of São Paulo, Brazil.

The State of SBo Paulo, located in the southeastern region of Brazil, covers an area of 247,320 km* and is inhabited by approximately 25 million persons distributed among 930 cities and towns. During the period 1827-1932 its population, which for almost 300 years had consisted basically of Portuguese colonists, African slaves, and mestizos, was supplemented by approximately 2.6 million immigrants; of these, Italians constituted some 36% ; Portuguese 15% ; Spaniards 14%; Japanese 4%; Germans, Arabs, Austrians, Russians, and Poles 20% ; and immigrants of other nationalities 11% (1). These groups, which came to be distributed unevenly within the state’s various economicdemographic subregions (Figure l), began an active process of miscegenation with the other basic elements of the state’s population. In addition, significant numbers of migrants came to SZo Paul0 from other parts of Brazil, the number of such people totaling about