50 samples of blood from patients diagnosed as betathalassemia in the center for blood transfussion and cryopreservation at minus 20oC and studied in the Mahidol University, where, DNA extracted by phenol and chloroform and the mutation analysed by technique of PCR and RDBH. The investigation of mutation that caused thalassemia help to establish the Center for the prenatal diagnosis, prevention and control of thalassemia in Vietnam.
beta-Thalassemia ; diagnosis ; mutation

Child ; Humans ; beta-Thalassemia ; diagnosis ; therapy

Beta-Thalassemia is a blood disease with beta-globin deficiency caused by a directly down-regulation in the synthesis of structurally normal beta chains. Vent DNA polymerase is a high-fidelity thermophilic DNA polymerase, and the fidelity 5 - 15 times higher than Taq DNA polymerase (1/31,000 vs. 1/290 - 1/2,400). Using ARMS PCR (Amplification Refractor Mutation System-PCR) with Vent DNA polymerase, we found that 9/28 (32%) of the tested beta-Thalassemia patients had the mutation at codon 17 and 4/28 (14%) at codon 41/42. This method can be applied for a rapid prenatal diagnosis of beta-Thalassemia disease and has public health significance.
beta-Thalassemia ; DNA ; Polymerase Chain Reaction ; Diagnosis

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 analyze the hematological characteristics of Chinese METHODS: Hemoglobin electrophoresis and blood routine test were used to analyze the hematological indexes of all peripheral blood samples，PCR-Flow fluorescent hybridization and Gap-PCR were used to detect the globin gene mutations and the data were analyzed statistically. RESULTS: The 3 types of deletion β- Thalassemia patients were showed as hypochromic small cell anemia. The MCH and MCV values of Taiwan type β-thalassemia patients were the lowest. The results of hemoglobin electrophoresis showed that the increasing of HbF was found in all of the 3 types. Except for the decreasing of Hb A2 in Chinese CONCLUSION Through analyze the hematological characteristics, it can be provide that the guidance for the differential diagnosis and genetic consultation of the three commonest deletion β-thalassemia in Chinese.
China ; Diagnosis, Differential ; Fetal Hemoglobin ; Humans ; Mutation ; Thalassemia ; 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*

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