Spectrum of β-thalassemia mutations in Guizhou Province, PR China, including first observation of codon 121 (GAA>TAA) in Chinese population

•We investigated the spectrum of β-thalassemia mutations in Guizhou Province.•Codon 17 (A → T) is the most prevalent mutation in Guizhou Province.•Codon 121 (GAA>TAA) was first found in Chinese population.•β-thalassemia mutations of 12 provinces in southern China were compared.

ObjectivesAlthough the population prevalence and mutation spectrum of β-thalassemia in most areas of south China have been characterized, the mutations have not been elucidated in Guizhou Province. The aim of this study was to investigate the spectrum of β-thalassemia in this province.Design and methodsWe detected and analyzed β-globin gene mutations in 407 β-thalassemia patients and carriers by PCR-based reverse dot blot (RBD) and direct sequencing methods.ResultsTwelve types of β-globin gene mutations were detected. Among the 12 different mutations, six mutations are common, accounting for 97% of mutated alleles. The most prevalent mutation is codon 17 (A → T) with an allele frequency of 40.7%. In addition, codon 121 (GAA>TAA), a rare dominant mutation, was detected in a patient with β-thalassemia intermedia for the first time in China.ConclusionsThe results of this study will be useful in genetic counseling and prenatal diagnostic service of β-thalassemia in Guizhou Province.