The distribution of
abnormal hemoglobins in Mexico is derived from surveys and from the study of patients with
hemolytic anemia. In aboriginal populations, more than 3,000 individuals have been studied: structural
abnormal hemoglobins are virtually absent in Mexican Indians and the sporadic finding of
hemoglobin S among them is due to admixture with Africans brought as slaves during the Spanish domination; two new variants of
hemoglobin (Mexico and Chiapas) were found in aborigines. The surveys in hybrid groups in selected areas of the country show that in some West and East Coast communities there are different frequencies of Hb S heterozygous, and that a high prevalence of Hb S trait has been found in some communities similar to that in some African areas. In a group of 200 subjects of a town located along the Gulf of Mexico Coast, 6% of Hb S and 15% of
thalassemia beta heterozygous is observed. In hospital surveys in two cities (Guadalajara and Puebla) several abnormalities of
hemoglobin have been identified (C, SC, Riyadh, Baltimore, Tarrant, Fannin-Lubbock and Mexico). In the study of isolated cases, mainly of patients with
hemolytic anemia,
hemoglobins I-Philadelphia, G-San Jose and D-Los Angeles are seen. The
thalassemias are the more frequent
hemoglobin abnormalities in selected populations of our country. In a community of Italian ancestry a frequency of 1.3% of
beta thalassemia 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 abnormalities with
hemoglobins S, Hb S + hereditary persistence of
fetal hemoglobin (HPFH) and Hb E as well as families with
delta-beta thalassemia, HPFH and
Hb Lepore-Washington-Boston have been also detected.