Genetic analysis of thalassemia among Tujia and Miao people of reproductive age in Chongqing / 中华地方病学杂志

ABSTRACT

Objective:The aim of this study was to investigate the carrier ratio and the genotype of thalassemia among Tujia and Miao people of reproductive age in Chongqing.Methods:According to forward-looking design and multi-stage stratified cluster sampling method, fasting venous blood samples of Tujia and Miao people of reproductive age were collected from 11 survey sites in Chongqing from March to July 2019. Gap-PCR and high-throughput sequencing were used to screen thalassemia genes.Results:A total of 516 Tujia people (258 males, 258 females) and 270 Miao people (139 males, 131 females) were included in this study, and their age were (28.63 ± 5.26) and (28.62 ± 5.35) years, respectively. About 5.04% (26/516) Tujia people carried thalassemia gene, with 1.94% (10/516) and 2.52% (13/516) for α and β thalassemia, respectively. Three kinds of new variants (1 case of each variant), HBA 2 c.46G>A (Gly>Ser), HBB c.*+129T>A and HBB c.-39T>G with unclear pathogenicity, were identified in Tujia people. About 7.78% (21/270) Miao people carried thalassemia gene, among these, α and β thalassemia were 3.33% (9/270) and 4.44%(12/270), respectively. The most common mutation type of α-globin gene was -α 3.7/in the two ethnic groups. Three kinds of β-globin gene mutation types, Codons 41/42 (-TTCT) beta 0, Codon 17 (A>T) beta 0 and IVS-Ⅱ-654 (C>T) beta +, were the most common in Tujia people. Meanwhile, the chief β-globin gene mutation type was Codons 41/42 (-TTCT) beta 0 in Miao people. Conclusions:The carrying rate of thalassemia gene is higher in Tujia and Miao people in Chongqing, and the genotypes of thalassemia gene are different between Tujia and Miao people. The clinical significance of three kinds of new variants with unclear pathogenicity should be focused on.