ABSTRACT
Objective:To study the genetic variation and distribution characteristics of thalassemia in people of childbearing age in Hubei Province, and to provide clinical basis for the local government decision-making departments to formulate and promote appropriate policies for prevention and control of thalassemia.Methods:Venous blood samples were collected from 44 849 people of childbearing age in hospitals in Hubei Province from May 13, 2019 to August 17, 2021. PCR-flow fluorescence hybridization and PCR+diversion hybridization were used to screen thalassemia genes. Spouses of those who tested positive were also tested for thalassemia genes. When both spouses carried the same type of thalassemia gene, the amniotic fluid of pregnant women was extracted for prenatal diagnosis and followed up.Results:Among the 44 849 people of childbearing age, 2 286 cases were diagnosed as thalassemia gene carriers through genetic testing, and the total detection rate was 5.10% (2 286/44 849). Among them, 1 488 cases were diagnosed as α-thalassemia, and the detection rate was 3.32% (1 488/44 849); 767 cases were diagnosed as β-thalassemia, and the detection rate was 1.71% (767/44 849); 31 cases were diagnosed as α-thalassemia combined with β-thalassemia, and the detection rate was 0.07% (31/44 849). The top three genotypes of α-thalassemia were -α 3.7/αα, -- SEA/αα, and -α 4.2/αα, accounting for 58.06% (864/1 488), 26.14% (389/1 488), and8.74% (130/1 488), respectively. The top three genotypes of β-thalassemia were β IVS-Ⅱ-654/β N, β CD41-42/β N, and β CD17/β N, accounting for 41.72% (320/767), 21.25% (163/767), and 16.04% (123/767), respectively. The main genotypes of α-thalassemia combined with β-thalassemia were -α 3.7/αα complex β IVS-Ⅱ-654/β N and -α 3.7/αα complex β CD41-42/β N, accounting for 29.03% (9/31) and 16.13% (5/31), respectively. A total of 59 people of childbearing age were conducted prenatal diagnosis, among fetus, there were 4 cases of severe thalassemia (2 cases of severe α-thalassemia, 2 cases of severe β-thalassemia), 5 cases of intermediate α-thalassemia, 5 cases of intermediate or severe β-thalassemia, 19 cases of mild thalassemia (8 cases of mild α-thalassemia, 11 cases of mild β-thalassemia), 13 cases of stationary α-thalassemia, and 1 case of stationary α-thalassemia combined with mild β-thalassemia, there were 12 cases without α-thalassemia or β-thalassemia genes. After follow-up, 4 cases of severe thalassemia, 2 cases of intermediate α-thalassemia, and 5 cases of intermediate or severe β-thalassemia were terminated pregnancy by the joint decision of both parents. Conclusions:In Hubei Province, the detection rate of thalassemia is high, and α-thalassemia is the main mutation type. The combination of thalassemia gene screening and prenatal diagnosis is of great significance in reducing the birth rate of children with thalassemia.
ABSTRACT
Objective:To analyze the incidence and characteristics of neonatal abnormal hemoglobinopathy in Wuhan and its surrounding areas.Methods:Dry blood spot samples of newborns (born from January 2020 to June 2021) sent to Hubei Neonatal Disease Screening Center were tested by hemoglobin capillary electrophoresis, and the newborns with abnormal hemoglobin bands were further tested for gene and statistically analyzed.Results:A total of 51 348 samples of neonatal dry blood spots were collected. According to electrophoresis analysis, abnormal bands were detected in 127 cases, and 78 cases were recalled for genetic test, the recall rate was 61.42%. Among them, 42 cases were diagnosed as abnormal hemoglobinopathy. Calculated according to the recall ratio, the detection rate of abnormal hemoglobinopathy was 0.13%. There were 11 cases of α-globin chain structural variation, most often were 3 cases of Hb Queens (27.27%) and 2 cases of Hb I (18.18%); moreover, there were 31 cases of β-globin chain structural variation, among which 11 cases of Hb J-Bangkok (35.48%), 8 cases of Hb E (25.81%) and 7 cases of Hb New York (22.58%) appeared more frequently. Among the 13 kinds of abnormal hemoglobins found, Hb I was located in N13/N(Bart) zone; Hb J-Bangkok and Hb J-Meerut were located in N12 zone; Hb New York and Hb Shenyang were located in N11 zone; Hb G-Coushatta, Hb G-Taipei and Hb Port Phillip were located in N5/N(D/G/K) zone; Hb Queens, Hb G-Honolulu and Hb Ottawa were located in N4/N(S) zone; Hb Montgomery and Hb E were located in N3/N (E) zone.Conclusion:The incidence of neonatal abnormal hemoglobinopathy in Wuhan and its surrounding areas is low, and main type of abnormal hemoglobin is β-globin chain structural variation.
ABSTRACT
Objective To analyze the fetal chromosomal karyotypes in prenatal diagnosis and the relationship between abnormal karyotypes and the indications of prenatal diagnosis. Methods Fetal chromosomal karyotypes were examined in 247 pregnant women (16 to 28 weeks' gestation) by amniocentesis. Results 14 abnormal chromosomal karyotypes were detected, the abnormal rate was 5.67%. Trisomy was the major abnormality, it was 7out of 14(50%), including 4 trisomy 21(42.86%)?2 trisomy 18(28.57%)?1 trisomy 13(14.28%).Balanced translocation was found in 6 fetuses, the frequency was 42.86%. In 18 pregnant women aged over 35 years,1 (5.56%) with trisomy 21 was detected, and 3 of trisomy 21 were in 229 pregnant women aged under 35 years (1.31%,P=0.235). 3 Trisomy were detected in 15 fetuses with ultrasonographic suspected abnormalities. Conclusions During the second trimester, in the pregnant women who had different indications for prenatal diagnosis, the rate of chromosomal abnormality was 5.67%. Trisomy was the most common abnormal karyotype. As one method of prenatal screening, ultrasound in the second trimester could increase the antenatal detection rate of fetal chromosomal abnormality.