OBJECTIVE: To investigate the genotype distribution of thalassemia in the population of childbearing age in Yulin area. METHODS: The polymerase reaction (PCR) combined with agargel eletrophoresis and reserve dot bolt hybridization was used to detected the α- and β-thalassemia gene in 31 769 cases of suspected thalassemia population at childbearing-age. RESULTS: A total of 22 254 cases were identified as thalassemia gene detetion or mutation in 31 769 cases with a detecting rate of 70.05%, and the detecting rate of α-thalassemia, β-thalassemia and α-combining β-thalassemia were 45.86% (14 569/31 769), 19.45% (6 178/31 769) and 4.74% (1 507/31 769) respectively. 28 kinds of α-thalassemia gene mutations were detected, the common mutations were as follows: -- CONCLUSION The detection rate of thalassemia gene is high in Yulin caildbearing-age population, and there is diversity in mutation spectrums of thalassemia. The most common genotypes are --
China ; Genotype ; Humans ; Mutation ; alpha-Thalassemia/genetics* ; beta-Thalassemia/genetics*

OBJECTIVE: To explore the cause of inconsistent genotypes for an α-thalassemia carrier by using two commercial genotyping kits. METHODS: GAP-PCR and PCR-reverse dot blotting (PCR-RDB) were employed to determine the genotype of the carrier, while Sanger sequencing was used to verify the results. RESULTS: Sequencing analysis demonstrated that the subject has carried a α1 globin gene with a 3.7 kb heterozygous deletion. In addition, two novel mutations, IVS-II-55(T>G) and IVS-II-119(G>TCGGCCC), were found in intron 2 of α2 globin gene. CONCLUSION The two mutations located in the binding regions of PCR primers have caused failure of PCR amplification and misreading of the genotype. Combination of clinical and hematological phenotypes is indispensible to infer the genotype of carriers for accurate diagnosis.
Genotype ; Heterozygote ; Humans ; Mutation ; alpha-Thalassemia ; genetics

OBJECTIVETo detect rare types of thalassemia mutations among southern Chinese population.

METHODSPeripheral blood samples from 327 patients from various regions of southern China were collected. The patients were suspected as rare-type thalassemia for their inconsistency between hematological phenotypes and results of routine mutation screening. The samples were further analyzed with GAP-PCR and DNA sequencing.

RESULTSOne hundred and eight cases were diagnosed as rare types of thalassemia. Among whom 10 rare α-globin gene mutations including --THAI, HKα, αααanti3.7, αααanti4.2, -α2.8, -α27.6, CD74 GAC>CAC (Hb Q-Thailand), CD30 (-GAG), CD31 AGG>AAG and CD118 (+TCA), and 12 rare β-globin gene mutations including CD37 TGG>TAG, CD39 CAG>TAG/CD39 CAG>TAG, β II-2 (-T), -90(C>T), -31(A>C), -88(C>T), CD7(-A), CD138(+T), CD89-93 (--AGTGAGCTGCACTG), CD54-58 (-TATGGGCAACCCT), Chinese G γ +(A γδβ)0 and Vietnamese HPFH (HPFH-6) were identified. -88(C>T) (HBB: c.-138C>T) and CD39 CAG>TAG (HBB: c.118C>T) were discovered for the first time in Chinese population. CD7(-A) (HBB: c.23delA) and CD138(+T) (HBB: c.416_417insT) were new types of β-globin gene mutations.

CONCLUSIONThe present study have enriched the mutation spectrum of thalassemia in southern China, which has provided necessary information for its diagnosis.

Humans ; Mutation ; Thalassemia ; genetics ; alpha-Globins ; genetics ; beta-Globins ; genetics

OBJECTIVE: To assess the value of high-throughput sequencing for the detection of thalassemia-associated variants in ethnic Li minority areas of Hainan, China. METHODS: In Baoting Li and Miao Autonomous County of Hainan Province, 1842 middle school students were randomly selected as the subjects, which included 1249 ethnic Lis, 454 ethnic Hans, and 139 individuals from other ethnic minorities. With DNA extracted from peripheral blood samples, gap-PCR combined with high-throughput sequencing were carried out to detect potential variants of the globin genes. RESULTS: In total 22 α-thalassemia genotypes, 5β-thalassemia genotypes, and 21 α-composite β-thalassemia genotypes were detected. The carrier rates for ethnic Li, ethnic Han and other ethnic minorities were 78.14%, 24.01%, and 28.06%, respectively. In addition, 22 fusion genes, 8 variants leading to abnormal hemoglobin, and 10 rare mutations were identified. CONCLUSION High-throughput sequencing can detect a wide range of genetic variants associated with thalassemia in the ethnic Li minority areas and has played an important role for the identification of fusion genes, variants underlying hemoglobin anomalies and rare mutations.
Humans ; alpha-Thalassemia/genetics* ; Genotype ; Ethnicity/genetics* ; Mutation ; High-Throughput Nucleotide Sequencing ; China ; beta-Thalassemia/genetics*

OBJECTIVE: This study was aimed at investigating the carrier rate of, and molecular variation in, α- and β-globin gene mutations in Hunan Province. METHODS: We recruited 25,946 individuals attending premarital screening from 42 districts and counties in all 14 cities of Hunan Province. Hematological screening was performed, and molecular parameters were assessed. RESULTS: The overall carrier rate of thalassemia was 7.1%, including 4.83% for α-thalassemia, 2.15% for β-thalassemia, and 0.12% for both α- and β-thalassemia. The highest carrier rate of thalassemia was in Yongzhou (14.57%). The most abundant genotype of α-thalassemia and β-thalassemia was -α ^3.7/αα (50.23%) and β ^IVS-II-654/β ^N (28.23%), respectively. Four α-globin mutations [CD108 (ACC>AAC), CAP +29 (G>C), Hb Agrinio and Hb Cervantes] and six β-globin mutations [CAP +8 (C>T), IVS-II-848 (C>T), -56 (G>C), beta nt-77 (G>C), codon 20/21 (-TGGA) and Hb Knossos] had not previously been identified in China. Furthermore, this study provides the first report of the carrier rates of abnormal hemoglobin variants and α-globin triplication in Hunan Province, which were 0.49% and 1.99%, respectively. CONCLUSION Our study demonstrates the high complexity and diversity of thalassemia gene mutations in the Hunan population. The results should facilitate genetic counselling and the prevention of severe thalassemia in this region.
Humans ; beta-Thalassemia/genetics* ; alpha-Thalassemia/genetics* ; Hemoglobinopathies/genetics* ; China/epidemiology* ; High-Throughput Nucleotide Sequencing

OBJECTIVE: To investigate the gene mutation and genotype distribution of thalassemia in the population of childbearing age in Chongzuo area of Guangxi. METHODS: Six α-thalassemia and 17 β-thalassemia gene mutations common in Chinese were detected by gap-polymerase chain reaction (gap-PCR) combined with agarose gel eletrophoresis and reserve dot bolt hybridization in 29 266 cases of child-bearing age suspected of thalassemia. RESULTS: A total of 19 128 (65.36%) cases were identified with thalassemia. The detection rate of α-thalassemia, β-thalassemia and α-combining β-thalassemia was 45.25% (13 242/29 266), 15.47% (4 526/29 266) and 4.65% (1 360/29 266), respectively. A total carrying rate of 8 kinds of α-thalassemia gene mutations was 26.74% (15 649/58 532), including 12.51% for --^SEA, followed by 5.70% for -α^3.7, and 0.24% for --^Thai. Among 32 α-thalassemia genotypes, the most common five were --^SEA/αα, -α^3.7/αα, α^CSα/αα, -α^4.2/αα and α^WSα/αα, accounting for 47.27%, 18.31%, 8.56%, 8.52% and 7.91%, respectively, as well as 0.97% for --^Thai/αα. A total carrying rate of 13 kinds of β-thalassemia gene mutations was 10.07% (5 897/58 532), including 3.63% for CD41-42, followed by 2.55% for CD17, and 0.003% for -50 (G>A). Among 17 β-thalassemia genotypes, the most common six were CD41-42/N, CD17/N, CD71-72/N, CD26/N, 28/N and IVSI-1/N, accounting for 36.15%, 25.81%, 9.43%, 8.18%, 8.09% and 7.75%. The homozygous genotype CD26/CD26 [hemoglobin (Hb): 121 g/L] and -28/-28 (Hb: 56 g/L) were respectively detected in one case, and double heterozygous genotype were detected in 5 cases, including 3 cases of CD41-42/CD26 (Hb: 41 g/L, 51 g/L, 63 g/L, respectively), 1 case of -28/IVSI-1 (Hb: 53 g/L), and 1 case of CD71-72/CD26 (Hb: 89 g/L), in which patients with moderate or severe anemia had a history of blood transfusion. Among 104 α-combining β-thalassemia genotypes, the most common were --^SEA/αα, -α^3.7/αα combining CD41-42/N and --^SEA/αα combining CD17/N, accounting for 12.13%, 9.63% and 9.26%, respectively. In addition, 1 case of --^SEA/-α^3.7 combining -28/IVSI-1 (Hb: 83 g/L) and 1 case of -α^3.7/αα combining CD41-42/ CD41-42 (Hb: 110 g/L) were detected without history of blood transfusion, while 1 case of α^WSα/αα combining CD41-42/CD17 (Hb: 79 g/L) and 1 case of --^SEA/αα combining CD17/-28 (Hb: 46 g/L) were detected with history. CONCLUSIONS The detection rate of thalassemia genes is high and the mutations are diverse in the population of childbearing age in Chongzuo area of Guangxi. The common deletion genotype is --^SEA/αα in α-thalassemia and CD41-42/N in β-thalassemia, and deletion genotype --^Thai is not rare. There is a certain incidence of intermediate and severe β-thalassemia, and most patients require transfusion therapy. The results are beneficial for genetic consultation and intervention of thalassemia.
Humans ; beta-Thalassemia/genetics* ; alpha-Thalassemia/genetics* ; Dipeptidyl Peptidase 4/genetics* ; China/epidemiology* ; Genotype ; Mutation

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 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 gene mutation types of thalassemia in the population of this area and the relationship between hematological phenotype and age in β-thalassemia. METHODS: 1 351 suspected cases of thalassemia were detected in the First Affiliated Hospital of Chengdu Medical College from June 2017 to June 2021. PCR-reverse dot blot hybridization(PCR-RDB) technique was used to detect the common α and β thalassemia gene types, then the data of MCV, MCH, MCHC and Hb of confirmed cases were collected. The heterozygotes of β-thalassemia were divided into 0-18 year group, 19-50 year group and >50 year group according to age, and the differences of hematological phenotypes among different groups were compared. RESULTS: Among the detected 1 351 samples， 523(38.71%) cases were diagnosed as thalassemia, 13 genotypes were detected in 260 cases (19.25%) with α-thalassemia; and 12 genotypes were detected in 252 cases (18.65%) with β-thalassemia; 9 genotypes were detected in 11 cases with αβ thalassemia. It was found that MCV and MCH were increased significantly in 0-18 year group, 19-50 year group and >50 year group, MCHC was highest in 0-18 year group, and Hb was the lowest in the >50 year group, and the difference was statistically significant（P<0.05）. CONCLUSION In this area, --^SEA/αα was the major genotype of α-thalassemia, and CD41-42 /N and IVS-II-654/N were the major genotypes of β-thalassemia. Morever, MCV and MCH were the lowest in the 0-18 year old group and the highest in the >50 years old group in heterozygotes of β-thalassemia. The influence of age on hematological parameters in the primary screening of thalassemia provides a certain reference value in clinical diagnosis and treatment.
China/epidemiology* ; Genotype ; Heterozygote ; Humans ; Mutation ; Phenotype ; alpha-Thalassemia/genetics* ; beta-Thalassemia/genetics*

OBJECTIVES: To investigate the distribution of genotypes of thalassemia in children in Guangxi, China. METHODS: A total of 30 417 children with positive results of thalassemia screening in the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2011 to December 2019 were enrolled. Single-tube multiplex PCR, agarose gel electrophoresis, and reverse dot blot hybridization technique were used for the detection of common α- and β-thalassemia genes. Gap-PCR or gene sequence analysis was performed for 2 703 children suspected of rare thalassemia. RESULTS: Among the 30 417 children with positive results of thalassemia screening, 23 214 (76.32%) were diagnosed with thalassemia, and the detection rates of α-thalassemia, β-thalassemia, and α-thalassemia with β-thalassemia were 47.77%, 23.75%, and 4.80% respectively. A total of 13 types of α-thalassemia alleles (18 480 alleles in total) were detected, mainly -- CONCLUSIONS There are diverse gene mutations and rich genotypes of thalassemia among children in Guangxi, and α-thalassemia is more common, with --
Child ; China/epidemiology* ; Genotype ; Heterozygote ; Humans ; Mutation ; alpha-Thalassemia/genetics* ; beta-Thalassemia/genetics*