OBJECTIVETo describe a community-based model for prevention and control of severe alpha and beta thalassemias in Zhuhai city of Guangdong province.

METHODSCouples for premarital medical examination or regular healthcare examination in pregnancy were enrolled in this prospective screening program, which was supported by the two-level network composed of 6 local hospitals for testing thalassemias and follow-up for genetic counseling. A conventional heterozygote screening strategy was used to determine alpha and beta thalassemia traits in women and their partners according to the standard procedures of hematological phenotype analysis. Then confirmative diagnosis of alpha and beta thalassemia was performed on those couples suspected at-risk for severe thalassemia by using the PCR-based molecular diagnostic assays. The couples at-risk for severe thalassemia were counseled and offered prenatal diagnosis and termination of pregnancy in case of an affected fetus.

RESULTSDuring the period between January 1998 and December 2005, the screened records included 85522 young females and their partners for premarital screening and 10439 pregnant women for prenatal screening, with 71.38% coverage of total population recorded in this city for premarital screening. Six thousands five hundreds and sixty-three individuals in total were found to be the carriers of thalassemias, with 4312 for alpha thalassemia (4.5%) and 2251 for beta thalassemia (2.3%), respectively. One hundred and forty-eight couples were diagnosed to be at-risk for thalassemias, including 103 for alpha thalassemia and 45 for beta thalassemia, respectively. Successful prenatal diagnosis was made for 142 (98 for alpha thalassemia and 44 for beta thalassemia) out of 148 (95.9%) pregnancies at-risk for severe thalassemias. Twenty-three cases of hydrops fetalis, 4 of Hb H diseases and 14 of beta thalassemia were identified. All 41 pregnancies with affected fetuses were voluntarily terminated. Thus, this has led to a marked decrease of severe thalassemia syndrome since the program started.

CONCLUSIONWe presented the first community-based prospective screening program in China for control of alpha and beta thalassemia in Zhuhai city with a population of 1.29 million through premarital or prenatal screening. This model could be used for control of thalassemias and other hemoglobinopathies in other regions of China and also in other developing countries.

China ; Humans ; Prenatal Diagnosis ; methods ; alpha-Thalassemia ; diagnosis ; genetics ; beta-Thalassemia ; diagnosis ; genetics

OBJECTIVE: To perform genetic analysis, prenatal diagnosis and preimplantation genetic diagnosis (PGD) in a family with a rare deletional β- thalassemia. METHODS: Hematological parameters of the peripheral blood collected from all the family members were analyzed by whole blood cell analysis and capillary zone electrophoresis (CZE). Polymerase chain reaction-reverse dot blot (PCR-RDB) was used to identify 17 common β- thalassemia gene mutations, the multiplex ligation-dependent probe amplification (MLPA) and gap-polymerase chain reaction (gap-PCR) were used to identify β- globin gene cluster deletions. Chorionic villus sample or umbilical cord blood was obtained for prenatal diagnosis. Oligo-cells from blastocyst biopsy were collected for preimplantation genetic diagnosis by whole genome amplification and next generation sequencing. RESULTS: The proband was a carrier of Taiwanese deletion β- thalassemia, two fetuses were both thalassemia majors. The PGD results showed that 6 of 11 tested embryos could be choose for transplantation. CONCLUSION The Taiwanese deletion is a rare type deletion of β- globin gene cluster, and it can lead to thalassemia intermedia or thalassemia major when compounded with other β- globin gene mutation. PGD is another choice for thalassemia couples.
Female ; Genetic Testing ; Humans ; Pregnancy ; Preimplantation Diagnosis ; Prenatal Diagnosis ; alpha-Thalassemia ; beta-Thalassemia ; genetics

OBJECTIVE: To investigate the type and distritution of thalassemia gene mutaitons in Hunan area, so as to provide evidence for prenatal screening, diagnosis and reduction of birth defects. METHODS: A total of 5018 cases from Maternal and Children Health Hospital of Hunan from June 2017 to Dec 2018 were undergone thalassemia gene mutation analysis. The reverse dot blot hydridization was used to detect 6 kinds of genotypes of α-thalassemia and 17 kinds of point mutations of β-thalassemia, and the detected data were analyzed statistically. RESULTS: 889 cases (55.9%) of α-thalassemia carriers were found, including 385 cases of silent α-thalassemia, 488 cases of α-thalassemia trait, 16 cases of Hb H disease. --/αα was the most common genotype in α thalassemia. 664 cases (41.7%) were diagnosed as β-thalassemia carriers, heterozygotes accounted for 99.8% (663/664), IVS-Ⅱ-654, CD41-42M and CD17M were the main genotypes, and compound heterozygote accounted for 0.2% (1/664). 38 cases were diagnosed as α-thalassemia combined β-thalassemia. CONCLUSION The constituent ratio of thalassemia gene mutations in Hunan has regional characteristics, --/αα is the most common genotype in α-thalassemia carrier. IVS-Ⅱ-654, CD41-42 and CD17 are common ones in β-thalassemia. The frequency of α-thalassemia combined with β-thalassemia is high.
Child ; China ; Female ; Genotype ; Heterozygote ; Humans ; Mutation ; Pregnancy ; Prenatal Diagnosis ; alpha-Thalassemia ; genetics ; beta-Thalassemia ; genetics

OBJECTIVE: To investigate the common genotypes of thalassemia of the pregnant woman in Wuhan area of China, and to make the prenantal gentic diagnosis for the fetus at high risk of thalassemia. METHODS: A total of 357 pregnant woman with the primary positive screening in Wuhan area were included in this study. Genotypes were measured with PCR-flow cytometry, and fluorescence hybridization was used for detecting thalassmia gene. The husbands of the pregnant women with thalassmia were recalled for genetic analysis of thalassemia, and 9 cases of fetuses with high risk of thalassemia were detected by amniocontesis after genetic counseling. RESULTS: In 357 cases of the pregnant women in Wuhan area, the 214 cases were diagnosed as thalassemia, 80 cases were diagnosed as alpha thalassemia (up to 90%), whose genotypes were determind as --/αα (78.75%) and -α/αα (15.00%), while 133 cases were determind with genotype of IVS-2-654/N (43.61%), CD41-42/N (20.30%) and CD17/N (19.55%) in beta thalassemia (up to 80%). 9 prenatal diagnosis continued pregnancy included 1case of -α/--, 1 case of -α/αα, 2 cases of --/αα, 2 cases of IVS-2-654/N and 3 cases of normal, however, the pregnancy in prenatal diagnosis of -α/-- voluntarily was terminated after genetic counseling. Follow-up results after delivery were consistent with prenatal diagnosis. CONCLUSION Minor and static thalassemia were very common in Wuhan area. Genetic detection after primary screening, genetic counseling and prenatal diagnosis in pregnant women could provide a theoretical basis for the development of regional specific prevention of intermedius and critical thalassemia which is meaning for rearing and bearing better children.
China ; Female ; Genetic Testing ; Genotype ; Humans ; Pregnancy ; Prenatal Diagnosis ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To investigate the relationship between umbilical cord blood erythrocyte index and thalasse-mia, and reveal its clinical value in the screening of thalassemia in neonates. METHODS: 2 919 cases of umbilical cord blood from neonatal who were born in Boai Hospital of Zhongshan Affiliated with Southern Medical University from July 2017 to December 2018 were collected, the routine blood tests were preformed to detect the umbilical cord blood. Thalassemia gene in peripheral blood of neonates was collected. The cut-off values of cord blood indexes were determined, and the sensitivity, specificity and other evaluation indexs were calculated. RESULTS: Among the cord blood in 2 919 neonates, 314 cases were detected out as thalassemia(positive rate: 10.76%). The average level of RBC and RDW in 2 605 children with non-thalassemia was lower than those with 314 children with thalassemia. The levels of Hb, MCV, MCH, MCHC, HCT, Hb/RBC and MCV/RBC in children with non-thalassemia were higher than those with thalassemia, and there were significant differences in the neonates between the two groups. The RBC and RDW levels of neonates in the α-thalassemia group were higher than those in the non-thalassemia group, while the levels of Hb, MCV, MCH, MCHC, HCT, Hb/RBC and MCV/RBC of neonates were lower than those in the non-thalassemia group. The levels of MCV, MCH and Hb/RBC of neonates in the β-thalassaemia group were lower than those in the non-thalassaemia group. The levels of MCV, MCH, Hb/RBC, and MCV/RBC of neonates in the complex thalassemia group were lower than those in the non-thalassemia group. When the cut-off value of MCV was set to 106.05 fl, the sensitivity was 0.548, and the specificity was 0.907, the specificity was the highest among all indexes. The area under the ROC curve of the combined diagnosis of MCH+MCV/RBC was the largest(0.807), the sensitivity was 0.710, the specificity was 0.841, the positive predictive value was 0.348, and the negative predictive value was 0.960. CONCLUSION The single indicator of umbilical cord blood red blood cells has advantages and disadvantages for the screening of thalassemia, but the combination of MCH+MCV/RBC can improve the accuracy of the screening or diagnosis of thalassemia, it also has a positive effect to the reduction of the birth rate of children with thalassemia major, which showed a high popularization value in primary hospitals.
Child ; Erythrocyte Indices ; Fetal Blood ; Humans ; Infant, Newborn ; Mass Screening ; alpha-Thalassemia/diagnosis* ; beta-Thalassemia

OBJECTIVE: To understand the genotypes and distribution characteristics of thalassemia in Baise, Guangxi Zhuang Autonomous Region, to provide references for the prevention and diagnosis of thalassemia in the region and improve the quality of eugenics. METHODS: 3 482 pregnant women and their spouses from January 2019 to August 2019 in Baise Maternal and Child Health Hospital for prenatal genetic diagnosis were selected, α, β- thalassemia genes were detected by Gap-PCR, PCR and DNA reverse dot hybridization, cases carrying thalassemia gene were confirmed and statistical analyzed. RESULTS: 2 260 samples (64.90%) carrying thalassemia gene were found, among which 1 459 cases (64.56%) were diagnosed as α- thalassemia, 617 cases (27.30%) as β- thalassemia, 184 cases (8.14%) as α complex β- thalassemia. Among 1 459 α- thalassemia genes, --SEA /αα(637 cases, 43.66%), -α3.7 /αα (306 cases, 20.97%), -αCS /αα(143 cases, 9.80%), -α4.2 /αα(124 cases, 8.50%) and -αWS /αα(77 cases, 5.27%) were the most common, while among 617 β- thalassemia genes, CD17 (229 cases, 37.12%), CD41-42 (213 cases, 34.52%), IVS-I-1 (41 cases, 6.65%), βE (38 cases, 6.16%) and CD71-72 (34 cases, 5.51%) were the most common. And --SEA /αα/ CD17 (24 cases, 13.04%), -α4.2 /αα/ CD17 (13 cases, 7.07%), -α3.7 /αα/ CD41-42 (12 cases, 6.52% ) and --SEA /αα/ CD41-42 (12 cases, 6.52%) were mainly found in 184 cases of α complex β - thalassemia. CONCLUSION Genotyes of thalassemia in Baise, Guangxi Zhuang Autonomous Region are complex and diverse. The prenatal screening and diagnosis of thalassemia in the region should be strengthened in accordance with the characteristics of genetypes in the region, in order to reduce birth defects and improve eugenics quality.
Child ; China ; Female ; Genotype ; Humans ; Mutation ; Pregnancy ; Prenatal Diagnosis ; alpha-Thalassemia/genetics* ; beta-Thalassemia/genetics*

OBJECTIVE: To explore the genotypes and prenatal diagnosis of thalassemia in couples of childbearing age in Quanzhou, Fujian Province. METHODS: Blood routine and hemoglobin electrophoresis were performed for initial thalassemia screening in 76 328 couples in Quanzhou region from July 2017 to July 2020. The couples with positive initial screening results further underwent thalassemia gene test. Couples carrying homotypic thalassemia genes underwent prenatal diagnosis in the second trimester. RESULTS: Among 76 328 couples of childbearing age, 1 809 couples of positive initial thalassemia screening were identified, with the positive rate about 2.37%. Further results of genetic detection of the 1 809 couples showed that 985 cases were diagnosed as α- thalassemia, of which --^sea/αα was the most frequency, followed by -α^3.7/αα and αα^QS/αα; 296 cases were diagnosed as β-thalassemia, the most frequency mutations were 654M/N and 41-42M/N; 26 cases of compound α and β-thalassemia were detected. In addition, 3 rare cases of thalassemia were detected, including --^THAI/αα, SEA-HPFH, and -α^6.9/--^sea. Among them, 108 couples were confirmed as homologous thalassemia, with the detection rate about 5.97%, including 96 couples of homologous α-thalassemia, 9 couples of homologous β-thalassemia, and 3 couples with one had compound α- and β-thalassemia. Among them, 17 couples with homologous α-thalassemia underwent prenatal diagnosis in the second trimester, of which 1 case of Hb Bart's Hydrops Syndrome, 3 cases of HbH disease, 9 cases of silent thalassemia or α-thalassemia minor, and 4 cases of healthy fetuses were detected. Fetal chromosome karyotype analysis showed that 16 cases were normal and 1 case diagnosed as Down syndrome. CONCLUSION Thalassemia screening in pre-marital and pre-pregnancy, and prenatal diagnosis can effectively reduce the birth of children with thalassemia intermediate and thalassemia major. It is necessary to perform chromosome karyotype analysis at the same time as prenatal diagnosis of thalassemia gene in order to avoid fetus with abnormal chromosome.
Child ; China ; Female ; Genetic Testing ; Genotype ; Humans ; Pregnancy ; Prenatal Diagnosis ; alpha-Thalassemia/genetics* ; beta-Thalassemia/genetics*

OBJECTIVETo establish a rapid and convenient method of reverse dot blot (RDB) analysis for detecting the point mutations of non-deletion alpha-thalassemia in Chinese.

METHODSLabel biotin to primers and amplify human alpha2 globin gene selectively, then hybridize PCR products with a set of oligonucleotide probes immobilized on strips, and develop colour to detect non-deletion alpha-thalassemia defects.

RESULTSThe PCR system using biotin-labeled primers could specifically amplify a 1085 bp fragment of human alpha2 globin gene which encompasses all six alpha-thalassemia mutations. After being hybridized with sequence-specific oligonucleotide probes and colour development, it could simultaneously identify all six types of non-deletion alpha-thalassemias encountered in Chinese.

CONCLUSIONThis method does not need semi-nested PCR, and the products amplified by biotinylated primers can be used directly to hybridize with the probes on strips under the identical conditions of hybridization. So, it is a specific and multiplex detection assay for screening non-deletion alpha-thalassemia defects in Chinese.

Humans ; Nucleic Acid Hybridization ; methods ; Point Mutation ; Reproducibility of Results ; alpha-Globins ; genetics ; alpha-Thalassemia ; diagnosis ; genetics

OBJECTIVE: To compare the performance of high-throughput sequencing technology in prenatal thalassemia screening in Zhuhai area through comparison with traditional methods. METHODS: A total of 1463 pregnant women were randomly selected. Following DNA extraction, high-throughput sequencing and conventional three-step thalassemia screening were carried out for each sample. Inconsistent results samples were validated by quantitative fluorescence PCR (QF-PCR) or Sanger sequencing. The results by the two methods were compared. RESULTS: Among the 1463 cases, 318 (21.74%) were detected by conventional method, which included 210 (14.35%) with α-thalassemia, 97 (6.63%) with β-thalassemia, 11 (0.75%) with composite α- and β-thalassemia. Meanwhile, 379 cases (25.91%) of thalassemia were detected by high-throughput sequencing, which included 260 (17.77%) with α-thalassemia, 107 (7.31%) with β-thalassemia, 12 (0.82%) with composite α- and β-thalassemia. Six one cases were missed by the conventional method, which yielded a missed diagnosis rate of 16.09%, including 50 cases of α- thalassemia,10 cases of β-thalassemia, and 1 case of α-compound β-thalassemia. No cases of thalassemia were missed by high-throughput sequencing, and 10 rare thalassemia genotypes were detected. CONCLUSION High-throughput sequencing technology can improve the detection rate of thalassemia and reduce the missed diagnosis rate. It has a high application value in prenatal thalassemia screening in Zhuhai area and can more effectively prevent the birth of patients with severe thalassemia.
China ; Female ; Genotype ; High-Throughput Nucleotide Sequencing ; Humans ; Mutation ; Pregnancy ; Prenatal Diagnosis/methods* ; Technology ; alpha-Thalassemia/genetics* ; beta-Thalassemia/genetics*

OBJECTIVE: To investigate the distribution of Ret-He and RBC in thalassemia and the value of combining HbA2 in the detection of thalassemia among patients with microcytic or hypochromic. METHODS: 145 patients with microcytic or hypochromic outpatient or hospitalization in our hospital from May 2018 to December 2019 were selected and were divided into the thalassemia group(68 cases) and the non-thalassemia group (77 cases), and at the same time, the patients were divided into four groups of the non-anemia, mild anemia, moderate anemia and severe anemia group according to the degree of anemia. The Ret-He, RBC, RDW-CV and HbA2 in patients were detected, and the distribution of these parameters were compared, and the joint detection of Ret-He, RBC and HbA2 about its sensitivity, specific and other indicators of auxiliary diagnosis of thalassemia were analyzed. RESULTS: Among patients with microcytic or hypochromic, according to the anemia grade Ret-He gradually decreased from the non-anemia group to the severe anemia group (P<0.05); while RDW-CV was increased gradually from the mild anemia group to the severe anemia group (P<0.05); both RBC and Ret-He were increased in the thalassemia group as compared with the non- thalassemia group (P<0.05); while RDW-CV was decreased in the thalassemia group as compared with the non-thalassemia group (P<0.05); meanwhile Ret-He in the α-thalassemia group was higher than that in the β-thalassemia group. ROC curve analysis showed that combined with HbA2, the specificity was 93.51%, the sensitivity was 66.18%, the positive predictive value was 90% and the negative predictive value was 75.189% when Ret-He was truncated with 19.25 pg and RBC was truncated with 4.95×10 CONCLUSION Among patients with microcytic or hypochromic, the distribution of RBC, Ret-He and RDW-CV was different in the thalassemia group and the non-thalassemia group, and was also affected by the degree of anemia. Combined Ret-He and RBC could improve the diagnostic specificity for thalassemia, which were screened by HbA2 in patients with microcytic or hypochromic.
Anemia, Iron-Deficiency ; Erythrocyte Indices ; Humans ; Proto-Oncogene Proteins c-ret ; ROC Curve ; alpha-Thalassemia ; beta-Thalassemia/diagnosis*