[Analysis of Gene Mutation Types in 141 Cases of α-Thalassemia in Honghe Prefecture, Yunnan Province].

Objective: To detecte the carrying rate, the type and distribution of α-Thalassemia gene mutation in Honghe Prefecture, Yunnan Province, and analyze the differences in average erythrocyte volume (MCV), mean erythrocyte hemoglobin content (MCH) and hemoglobin among different types of α-Thalassemia.

Methods: The DNA samples from small cell hypochromic carriers or anemia patients and women of childbearing age who underwent hematological screening in The First People's Hospital of Honghe State was from 2015 to 2019 were enrolled and analyzed, and the mutation types and frequency of alpha-thalassemia positive rate were diagnosed by PCR reverse dot blot or PCR fluorescence dissolution curve.

Results: Among the 1 016 samples, 141(13.88%) of the patients were diagnosed as α-thalassemia. The α-thalassemia was subdivided into 3 types, silent (36.17%), minor (51.77%), and HbH disease (12.06%), and the MCV, MCH and HB levels were detected and showed a obvious decrease trend with significant difference (P < 0.05). The gene mutation types were 9 kinds, the deletion type gene was mainly --SEA (51.06%), followed by -α/αα deletion (29.79%), the α- mutation type gene was mainly αα(3.55%). The absence of complex heterozygote was most common, which was 17 cases, accounting for 12.77%, mainly --/-α (10.64%). The areas were mainly distributed in Mengzi (47.52%), followed by Jinping (17.02%). Ethnic groups were mainly distributed in Han nationality (49.65%), followed by Zhuang (15.60%), Yi (3.48%) and Dai (7.09%). The patients with double heterozygous mutation was slightly higher in Mengzi than that in Jinping County (4.26% vs 3.55%), the Dai (2.13%) showed Zhuang ethnic group (2.13%) had the relatively high incidence except the Hans, and showed the most serious anemia.

Conclusion: Alpha-thalassemia in Honghe prefecture of Yunnan Province shows complex genetic diversity and significant genetic heterogeneity, and the mainly type of gene mutation is --SEA and --/-α, which is mainly distributed in Han, Zhuang and Dai ethnic groups in Mengzi, Jinping. The anemia index of HbH group is the most obvious, and it is significantly different from other groups.