Detection of common deletional of α-thalassemia 3.7 kb from metropolitan region of manaus, Amazonas, Brazil

Abstract

Background: Alpha Thalassemia (α-thal) is a heterogeneous group of hereditary alterations caused by deletions that affect alpha regulatory genes, and the 3.7Kb deletion is the most frequent worldwide. The prevalence ranges from 20% and 35% in Brazil, depending mainly on race, predominant in Afro-descendants. Purpose: The aim was to determine α-thal -α3.7Kb and -α4.2Kb deletions, estimating their frequency in individuals from six regions of Amazonas State. Methods: Volunteers age between 18-59 years old of both genders participated in the study. Blood was collected from March 2014 to September 2017 at the health centers of each participant city. α-thal3.7Kb was performed by GAP-PCR, while α-thal4.2Kb by Multiplex-PCR. The total samples collected from each city were: Manaus (capital), 356 (19.7%); Iranduba 232 (12.8%); Manacapuru, 287 (15.9%); Presidente Figueiredo, 370 (20.5%); Itacoatiara, 301 (16.6%); and Coari, 263 (14.5%). Results: The average age among males was 35.3±14.8, while for females, it was 36.7±14.9 years old. Microcytosis (MCV <80fL) was found in 158 individuals (8,46%) and α-thal diagnosed in 143 individuals (7.9%), and all of these individuals carried the 3.7Kb deletion 5.95% in heterozygous and 1.95% in homozygous. α-thal4.2kb was not found in any volunteer. The association analyses to the α-thal3.7kb genotypes were statistically significant for all hematological parameters (p