Prevalence and Genetic Analysis of α- and β-Thalassemia and Sickle Cell Anemia in Southwest Iran

Abstract

This prospective study assessed the prevalence and genetic analysis of α - and β -thalassemia and sickle cell anemia (SCA) in Southwest Iran. Hematological indices were measured in 17,581 couples living in Khuzestan Province, Southwest Iran. Individuals with mean corpuscular volume <80, mean corpuscular hemoglobin <27, hemoglobin A2 ≥3/5 were considered as β -thalassemia traits. Prevalence of minor β -thalassemia, α -thalassemia, SCA, iron deficiency anemia, and silent thalassemia were respectively identified in 995 (5.6%), 1169 (6.65%), 1240 (7.05%), 911 (5.18%), and 1134 (6.45%) individuals using a multiplex amplification refractory mutation system, and direct DNA sequencing of globin genes. Three codons IVS-II-1 (G → A; 26%; n = 13), IVS-I-1 (G → T; 16%; n = 8), and IVS-I-110 (G → A; 14%; n = 7) were the most frequent mutants and IVS-II-1 was the most common β -thalassemia mutation. Also, based on a gap-polymerase chain reaction assay, genotype frequencies of α -globin mutations were − α 3.7 kb (50%; n = 25), Med/ αα thal (12%; n = 6), and − α 4.2/ αα (10%; n = 5), which were the most frequent deletion mutants (72% in total). The most common deletion (50%) was − α 3.7 kb . Our data suggest that the population of Southwest Iran is at high risk of α - and β -thalassemia caused by these deletion mutants and SCA. Our findings will be useful for developing an efficient control program and genetic counseling.

Evaluation of the Prevalence of Thalassemia and Sickle Hemoglobin in Marriage Applicants Referring to the Genetic Disease Counseling Center in Kazeroun, Iran during 2014-2018

“…Based on the results of the present study, the prevalence of sickle cell hemoglobin in marriage applicants was 0.24 (24% for the total study years: 8% in 2014, 1% in 2015, 5% in 2016, 1% in 2017 and 9% in 2018). In the study by Foruzan Nejad et al in Ahvaz, the prevalence of sickle hemoglobin was 7.05% [14]. In the study by Canton et al and in the Kagura region, the respective prevalence was 10% [28].…”

“…The results of the current study showed that the prevalence of alpha thalassemia in marriage applicants was 0.58 (58% in all study years: 1.4% in 2014, 1.5% in 2015, 1.4% in 2016, 1.4% in 2017, and 1.5% in 2018). In the study by Forouzan Nejad et al, the prevalence of α-thalassemia was 65.6% in Ahwaz [14]; in the study by Valizadeh et al, the prevalence of alpha thalassemia among marriage applicants was 53.3% [20]; in the study by Zandi et al, in Khuzestan, it was 9% [21], and in the southern regions of Iran, it was over 30% [22]. In the study by Alkara et al in Emirate, the respective prevalence was 49% [23], and in the study by Borgrus et al in Brazil, it was 42.8% [24].…”

“…The results of the present study showed that the prevalence of anemia among marriage applicants was 0.24 (24% in the total study years: 6% in 2014, 4% in 2015, 5% in 2016, 4% in 2017, and 5% in 2018). In the study by Foruzan Nejad et al in Ahvaz, the prevalence of anemia was reported to be 5.18% [14].…”

“…The prevalence of thalassemia was 5.5% in a study conducted by Forouzan Nejad et al in Ahwaz in 2018 [14]. In a study conducted in Pakistan in 2015, the prevalence of thalassemia was 6.5% [15].…”

Prevalence and Molecular Spectrum of α- and β-Globin Gene Mutations in Hainan, China

“…The speci c phenotypes and frequency are shown in Table 6. The three most frequent types in Han people were -α 3.7 /αα, -α 4.2 /αα and -α WS , all of which were accompanied by CD41/42, accounting for 19.48%, 16.29% and 16.86% respectively. The three most frequent types in Li people were -α 3.7 /αα, -α 4.2 /αα and -SEA/αα, all of which were accompanied by CD41/42, accounting for 21.45%, 21.29% and 11.28%, respectively.…”