The value of combined detection of HbA2 and HbF for the screening of thalassemia among individuals of childbearing ages / 中华医学遗传学杂志

OBJECTIVE@#To assess the application value of combined detection of HbA2 and HbF for the screening of thalassemia among a population of childbearing age in Quanzhou, Fujian, and determine the optimal cut-off values for the region.@*METHODS@#Capillary hemoglobin electrophoresis and genetic testing for α and β globin gene mutations were simultaneously carried out on 11 428 patients with suspected thalassemia. Statistical methods were used to analyze the distribution of various types of thalassemia and compare the performance of HbA2 and HbF measurement for the screening of various types of thalassemia. The optimal cut-off values for HbA2 and HbF were determined with the ROC curves.@*RESULTS@#4591 patients with α, β, and αβ compound thalassemia were identified by genetic testing. The most common genotypes for α and β thalassemia included --SEA/αα and β654/βN, β41-42/βN, and β17/βN. The ROC curves were drawn to compare the performance of HbA2 screening for α-, β-, αβ-compound, static α-, mild α-, and intermediate α-thalassemia, and the maximum area under the curves was 0.674, 0.984, 0.936, 0.499, 0.731, 0.956, and the optimal cut-off values for HbA2 were 2.45%, 3.25%, 3.65%, 2.95%, 2.55%, 1.75%, respectively.@*CONCLUSION@#HbA2 is an efficient indicator for identifying intermediate types of α-, β-, and αβ compound thalassemia. The combination of HbA2 and HbF measurement can effectively detect carriers for β-thalassemia mutations.

Screening for thalassemia and analysis of gene test results in 41 026 couples of childbearing age in Quanzhou City Fujian Province / 中华地方病学杂志

Objective To investigate the screening and gene test of thalassemia in couples of childbearing age in Quanzhou City Fujian Province.Methods A prospective design was used to collect 41 026 pairs of marriage and excellent blood samples from 12 counties in Quanzhou City,Fujian Province from July 2017 to July 2018.To analyze screened the genetic test results and genotyping of positive thalassemia couples.Firstly,the erythrocyte mean corpuscular volume (MCV) and erythrocyte mean corpuscular hemoglobin (MCH) were used for primary screening.Both sides of the couple were performed hemoglobin electrophoresis when at least one of the couples was screened positive.Couples were performed thalassemia gene detection when blood routine or hemoglobin electrophoresis of the couples was positive.The characteristics of genotypes,homologous carriers and distribution of gene mutations in Quanzhou City were analyzed.Results Among 41 026 couples of childbearing age,4 470 couples had abnormal blood routine examination results in at least one of the couples,the rate of positive screening was 10.90％.There were 952 couples who represented abnormal blood routine or hemoglobin abnormal electrophoresis.Totally 658 cases were diagnosed as thalassemia after thalassemia gene detection,and the diagnosis rate was 34.56％.Totally 493 cases of α-thalassemia were detected,and the higher genotypes were:--SEA/αα,-α3.7/αα and ααQS/αα;and 155 cases of β-thalassemia were detected,and the higher genotypes were:IVS-Ⅱ-654/N,CD41-42/N,CD17/N,βE/N,-28/N;10 cases of α complex β thalassemia were detected.Totally 56 high-risk couples with homologous thalassemia gene were detected,including 50 pairs of homologous α-thalassemia,4 pairs of homologous β-thalassemia,and 2 pairs of homologous couples with α complex β thalassemia.The rate of diagnosis and detection rate of homologous thalassemia in different counties of Quanzhou were quite different (x2 =41.939,21.129,P ＜ 0.05).Among them,the rate of diagnosis in Dehua County was the highest (53.13％,85/160),followed by Yongchun County (39.38％,63/160) and Nan'an City (37.73％,123/326).In addition,the detection rate of homologous thalassemia in Dehua County was the highest (15.00％,12/80),followed by Anxi County (8.44％,13/154) and Yongchun County (7.50％,6/80).Conclusions The incidence of thalassemia in couples of childbearing age in Quanzhou is higher,mainly due to α-thahssemia.The high-risk type of homologous carrier is present in α-thalassemia,which should be paid attention to the prevention and control of thalassemia.

Analysis a family with partial Xq deletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze partial deletion of the long arm of X chromosome in a family and explore the mechanism underlying its phenotypes.</p><p><b>METHODS</b>G-banding technique was employed to analyze the karyotypes of the subjects, and fluorescence in situ hybridization (FISH) was used to analyze their X chromosomes with Xpter, Xqter and WCPX probes.</p><p><b>RESULTS</b>The karyotypes of the proband, her mother and her fetus were all 46,X,del(X)(q24). Combined FISH and karyotyping analysis suggested that the proband and her fetus both carried a Xq24q27.3 deletion.</p><p><b>CONCLUSION</b>The Xq24q27.3 deletion carried by the family is closely related with premature ovarian failure but not with short stature, gonadal dysgenesis and primary amenorrhea.</p>