[Analysis of rare mutations associated with Thalassemia and their hematological characteristics in Chenzhou region of Hunan Province].

Objective: To explore the distribution and hematological characteristics of rare thalassemia-associated mutations in Chenzhou region of Hunan Province with an aim to provide a basis for genetic counseling and effective prevention.

Methods: A total of 37 370 individuals enrolled from January 2015 to December 2021 were screened by routine blood test and hemoglobin electrophoresis. The genotypes were determined with high-throughput sequencing.

Results: A total of 8 455 thalassemia mutations (including 185 rare ones) were detected, which had involved 27 mutational types. Rare type α-Thalassemia --THAI and CD31 (AGG>AAG) have the typical microcytic hypochromic hematological features, whilst SEA-HPFH, CD14 (CTG>-TG), CD37 (TGG>TAG), -90(C>T), Codon 15 (G>A), IVS-I-128 (T>G), CD86 (GCC>GC-) and Chinese Gγ+(Aγδβ)0 had typical microcytic hypochromic and β-thalassemia-associated hematological features of elevated HbA2 or HbF. In addition, the -50（G>A）heterozygotes of β-thalassemia had normal or slightly decreased MCV and MCH without an increase in HbA2.

Conclusion: Various forms of thalassemia-associated mutations have been identified in the Chenzhou region of Hunan Province. Above finding has facilitated development of preventive and control strategies for thalassemia as well as birth health programs.