Mutation spectrum of thalassemia among pre-pregnant adults in the Jiangsu Province by capillary electrophoresis-based multiplex PCR assay

BackgroundThalassemia is a common genetic disorder in southwestern China, and an increasing number of cases from eastern China have been recently reported. Here, we developed a rapid, convenient, and accurate assay to evaluate the mutation spectrum of thalassemia in eastern China.MethodsA carrier screening assay for 61 hotspot variants among HBA1/HBA2 and HBB (OMIM: 141800, 141850, and 141900) genes was developed by SNaPshot/high-throughput ligation-dependent probe amplification (HLPA) technology. We used this assay to detect the mutation spectrum of thalassemia in individuals from eastern China and compared with the data collected from literatures focused on southern and northern China for variant distribution.ResultsAmong 4276 tested individuals, 2.62% (112/4276) were alpha-thalassemia carriers, with 90 carrying one deletion or mutation and 22 carrying two deletions. 0.40% (17/4276) were beta-thalassemia carriers, and the most common variant of beta-thalassemia was c.126_129delCTTT (29.41%) followed by c.316-197C>T (23.53%). The genotype distribution in our study was similar to those from southern China populations.ConclusionThe Chinese population from different regions presented comparable mutation spectrum of thalassemia, and the SNaPshot/HLPA technique may serve as a capable assay for a routine genetic test in clinical practice with its accurate, rapid, and inexpensive advantage. SNaPshot/HLPA can accurately and rapidly detect HBA1/HBA2 and HBB gene variants at a comparable performance and lower cost as compared with NGS. The carrier rate of alpha-thalassemia was approximately 1 in 38 (2.62%) in 4276 individuals, and 1/251 (0.40%) were beta-thalassemia carriers. The ratio of the most prevalent deletions and mutations of alpha-thalassemia, -alpha 3.7, --SEA/alpha alpha, alpha alpha alpha anti4.2/-alpha 3.7, -alpha 4.2, c.369C>G, and c.427T>C, was 50.90%, 16.96%, 15.18%, 9.82%, 2.68%, and 2.68%, respectively. The most common mutation of beta-thalassemia was c.126_129delCTTT (29.41%), followed by c.316-197C>T (23.53%). The mutation genotype distribution in our study was similar to those in southern China populations. image