The incidence of thalassemia and the analysis of thalassemia-associated gene in children in Guangzhou region

Objective: To investigate the incidence of thalassemia(thal) and the distribution of the Chinese common thal-associated genes in children in Guangzhou region.Methods: Samples from 4990 children in Guangzhou region were detected for α-thal or β-thal by means of hematologic examinations such as fully automatic hemoglobin agarose gel electrophoresis mainly.Then 287(including 103 with α-thal and 177 with β-thal as well as 7 with both α-thal and β-thal) of the positive samples were diagnosed as α-thal by means of a single tube multiplex PCR based the gap PCR principleand as β-thal with PCR-RDB method for common 18 β-thal gene mutations in Chinese.Results:(1) Among the 4990 children,carriers were screened as follows:427 were α-thal and 562 β-thal and 7 bothα-thal and β-thal,which meant the incidence of α-thal was 8.56% and that of β-thal was 11.26%,that of bothα-thal and β-thal was 0.14%.(2)All 110 α-thal carriers(including 7 with both α-thal and β-thal) diagnosed by genic detection were identified as gene deletions of which the constituent types were as follows by calculated with chromosome:——SEA was 72.80%,-α3.7 was 18.38% and-α4.2 was 8.82%.In all 184 carriers detected by genic detection for β-thal,10 different β-thal mutations which made up 22 kinds of genotypes were identified Among the 181 diagnosed carriers.The most five commonest β-thal gene mutations were as follows: CD41-42(45.71%),IVS-Ⅱ-654(25.79%),CD17(14.03%),TAT box-28(8.15%),CD71-72(3.17%).Conclusion: Guangzhou region is one of the areas with high risk of α-thal and β-thal,where the β-thal genic situation is the most complex in China.So it is recommended that more attention should be paid to detect the carriers of thal in childhood by hematologic screening and common genic diagnosis in the area with high risk of α-thal and β-uhal.