Types and frequencies of hemoglobin disorders in the pacific coast of four states of Mexico.

INTRODUCTION Hemoglobin disorders are classified into three main groups: structural variants, thalassemias (thal) and hereditary persistence of fetal hemoglobin (HPFH). OBJECTIVE. This study describes the types and frequencies of hemoglobinopathies from four states of the Pacific coast of Mexico (Jalisco, Colima, Nayarit and Michoacan). MATERIAL AND METHODS. We studied 1513 Mexican individuals by hematological and biochemical analysis following the conventional methods, DNA analysis was carried out in abnormal samples. RESULTS. The frequency of hemoglobinopathies was 1.258%. Structural variants were the most common type (0.726%), with seven carriers (0.462%) and one homozygote (0.066%) for Hb S, and three heterozygotes of the following hemoglobins: C (beta6 Glu-->Lys), Fannin-Lubbock I (beta119 Gly-->Asp) and Colima (beta49 Ser-->Cys), with a frequency of 0.066% each. We observed a frequency of 0.466% for the thalassemia group, with one homozygote for the alpha3.7 (-thal) allele (0.066%), and 6 heterozygotes for beta-thal (0.40%), with the allele IVS1:110 G-->A in three subjects, and the alleles Cd 39, IVS1:5 G-->A and -28 A-->C in the three other. HPFH was detected in one subject (0.066%). Jalisco and Colima had the highest frequencies of hemoglobinopathies, 3.015% and 1.331% respectively, and the latter showed the most diversity of hemoglobin disorders. CONCLUSIONS The observed heterogeneity of types and frequencies of hemoglobinopathies in the regions studied illustrate the importance of further investigation of these abnormalities in Mexico.