Analysis of β-thalassemia mutations in Fujian province

Abstract

Objective To explore the prevalence and spectrum of β-thalassemia mutations in Fujian province,and to provide a reference for prenatal diagnosis and genetic counseling in this population.Methods Two thousand three hundred and one blood samples were randomly selected from 9 different areas of Fujian province from May 2008 to December 2010.PCR and reverse dot blot hybridization (RDB) were adopted for detection of the 17 common types of mutation,and the frequency of each genotype of β-thalassemia mutations was calculated.The β-globin gene of unknown positive samples were analyzed directly with DNA sequencing.Results Three hundred and fifty-nine cases were detected with β-thalassemia mutations of the 2301 copy blood samples submitted,and the detection rate was 15.60％ (359/2301).Of the mutated genes,12 different mutations were identified,namely IVS-2-654(C→T),CD41-42(-TCTT),CD17(A→T),-28(A→G),CD27-28(+C),CD26(G→A),CD71-72(+A),IVS-1-1(G→T),CD43(G→T),-29(A→G),initiation codon ATG→AGG and CD36(-C).Mutation frequencies were 46.54％ (175/376),33.24％ (125/376),9.31％ (35/376),5.05％ (19/376),2.13％(8/376),1.33％(5/376),0.80％(3/376),0.27％(1/376),0.27％(1/376),0.27％(1/376),0.53％(2/376),and 0.27％(1/376),respectively.The most common mutations were IVS-2-654 (C→T) and CD41-42 (-TCTT),which accounted for 79.78％(300/376) of total genetic mutations.In addition,a novel β-globin gene mutation CD36 (-C) allele was detected for the first time,the deletion of a nucleotide C at code 36 within exon 2 lead to a frameshift mutation that could result in a premature termination at code 60.Conclusions β-thalassemia mutations in Fujian province are complex with significant genetic heterogeneity.We present for the first time the detection of a new β-thalassemia mutation in the population:CD36(-C),which provides valuable information for genetic counseling and prenatal diagnosis in Fujian province. Key words: 3-thalassemia; Genotype; Reverse dot blot hybridization