Analysis of gene mutation type and frequency in children with thalassemia aged 0-18 years in Chengdu, Sichuan / 中华检验医学杂志

ABSTRACT

Objective:To analyze the type and frequency of thalassemia gene mutation in children aged 0 to 18 years in Chengdu.Methods:A total of 568 children from Chengdu, who were initially positive for thalassemia during screening from September 2018 to July 2021, were recruited. Among them, there were 308 males and 260 females. The type of mutation and distribution of α and β types of thalassemia in this cohort was analyzed utilizing PCR reverse dot blot.Results:Among the 568 children, 356 were genetically diagnosed as thalassemia, with a total positive rate of 62.68%. Among them, there were 140 cases of α-thalassemia with a positive rate of 24.65%, and 202 cases of β-thalassemia with a positive rate of 35.56%. There were 14 carriers of α-complex β-thalassemia gene, and the positive rate was 2.46%. Among these cases, the types of α-thalassemia gene mutation were mainly αα/--sea (79.29%), αα/-α3.7 (7.86%), and-α3.7/--sea (7.14%) genotypes, accounting for 94.29% of all types. In the 202 β-thalassemia patients, 199 heterozygous mutations were identified, mainly including cd17(A?T) (36.13%), cd41-42(-TCTT) (32.68%), IVS-2-654(C?T) (20.79%), and accounting for 88.61% of all types of gene mutation, and 3 compound heterozygous mutations were detected. α-complex β-thalassemia was detected in 14 patients, including cd41-42(-TCTT)/-α3.7, VS-2-654(C?T)/--sea, cd17(A?T)/-α3.7 and cd41-42(-TCTT)/--sea, which accounting for 57.14% of all types of gene mutation. Our results showed that there is no sex difference between α and β thalassemia in Chengdu area, whereas the prevalence of α combined with β thalassemia is higher in males ( P=0.003). Conclusions:The type of α-thalassemia mutation in Chengdu is mainly αα/--sea, whereas β-thalassemia with cd17 (A?T) mutations and α-complex β-thalassemia are more frequent in males. This study provides a reference for the formulation of prevention and control strategies for thalassemia in Chengdu.