ABNORMAL-HEMOGLOBINS AND THALASSEMIAS IN MEXICO

The distribution of abnormal hemoglobins in Mexico is derived from sur veys and from the study of patients with hemolytic anemia. In aborigin al populations, more than 3,000 individuals have been studied: structu ral abnormal hemoglobins are virtually absent in Mexican Indians and t he sporadic finding of hemoglobin S among them is due to admixture wit h Africans brought as slaves during the Spanish domination; two new va riants of hemoglobin (Mexico and Chiapas) were found in aborigines. Th e surveys in hybrid groups in selected areas of the country show that in some West and East Coast communities there are different frequencie s of Hb S heterozygous, and that a high prevalence of Hb S trait has b een found in some communities similar to that in some African areas. I n a group of 200 subjects of a town located along the Gulf of Mexico C oast, 6% of Hb S and 15% of thalassemia beta heterozygous is observed. In hospital surveys in two cities (Guadalajara and Puebla) several ab normalities of hemoglobin have been identified (C, SC, Riyadh, Baltimo re, Tarrant, Fannin-Lubbock and Mexico). In the study of isolated case s, mainly of patients with hemolytic anemia, hemoglobins I-Philadelphi a, G-San Jose and D-Los Angeles are seen. The thalassemias are the mor e frequent hemoglobin abnormalities in selected populations of our cou ntry. In a community of Italian ancestry a frequency of 1.3% of beta t halassemia trait is found. In our laboratory, 76% of the abnormalities are cases of beta thalassemia trait. Patients with Hb H disease, beta thalassemia (homozygous and heterozygous) and combinations of these a bnormalities with hemoglobins S, Hb S + hereditary persistence of feta l hemoglobin (HPFH) and Hb E as well as families with delta-beta thala ssemia, HPFH and Hb Lepore-Washington-Boston have been also detected.