The Screening And Epidemiological Investigation Of Thalassemia In Children From Shanghai And Other Places

Thalassemia,as one class of hemoglobinopathy,often coexists a variety of hemoglobin variants,leading to a broad spectrum of clinical and hematological phenotypes,which also increased the genotype complexity of thalassemia.However,according to the reported paper and database,rare source showed about the epidemiological information on children associated with a large proportion of floating population in large cities,especially the Yangtze River Delta.In the previous study,the quantitative method of analyzing HbF/HbA₂ was optimized and the scheme for screening thalassemia was established.The erythropoietic parameters were detected and HbF/HbA₂ were quantified by automated HPLC from the peripheral blood in 200 genetically diagnosed thalassemic patients and 62 normal individuals.The HPLC program can also identify hemoglobin variants.The internal quality control system Multiple Westgard rules 1_2s/1_3s2_2sR_4s was also established to ensure the accuracy and efficiency of all figures and monitor the whole experimental process at real time.Furthermore,the experimental cost was also decreased.The cut-off value of the two indicators HbF and HbA₂ was confirmed as 1.05%and 3.75%,respectively through the ROC analytical approach.We screened 491 clinical cases by the combined screening scheme,all of which were also tested for genetic diagnosis.The genetic diagnostic results were used as a gold standard.The epidemiological characteristics were analyzed on the children group with thalassemia in this area.The results suggested that the sensitivity and specificity of this screening program were 99.7%and 99.8%,which once again verified the combined screening program an ideal scheme on large scale screening thalassemia,especially for beta thalassemia.The geographical distribution of 380 genetically positive cases of children with thalassemia is Jiangsu 17.4%,Zhejiang 21.8%and Shanghai 60.8%,respectively.Furthermore,different types of thalassemia have the specific retention time and distinctive detected range of HbF/HbA₂.The retention time of HbF/HbA₂ among H disease,E disease and severe thalassemia showed significant difference with normal control samples.The retention time of HbA₂ in beta thalassemia was slightly ahead of the normal controls.The hematology parameter MCV/MCH and the expression levels of HbF/HbA₂ in different genotypes in the Yangtze River Delta were also distinctive.Apart from these high incidence provinces,the mean value of MCV,MCH and HbA₂ slightly higher than the data reported on the whole.However,the percentage of HbF shows great difference in different thalassemic types.The parameters of the silent type of alpha thalassemia are relatively close to the reported data.The erythropoietic parameters of H disease were unstable with great variation.The percentage of HbA₂ was slightly higher than the values reported.