Hemoglobins, Abnormal ; Humans ; alpha-Thalassemia ; complications ; beta-Thalassemia ; complications

OBJECTIVETo explore the frequency and spectrum of thalassemia gene mutations of the population in Sanya area of Hainan province in China.

METHODSThe type and frequency of gene mutation in 1060 patients with suspected thalassemia were analyzed by Gap-PCR and reverse dot blot (RDB).

RESULTSThe detection on mutation of thalassemia gene were found in 539 suspected thalassemia patients, the total detected rate was 50.85% (539/1060), out of them 330 (31.13%) were diagnosed with α-thalassemia, 162 (15.28%) with β-thalassemia, and 47 (4.43%) as carriers of both α and β-thalassemia. In α-thalassemia patients, genotype were as follows in proper order--SEA/αα (9.25%)、-α /αα (5.94%)，HbH (5.56%)，-α /αα (5.00%)，-α /-α (2.36%)，-α /-α (1.70%), and -α/-α(1.32%). In β-thalassemia patients, there were 9 gene mutations: CD41-42 (9.8%), CD17 (1.32%), 654 (1.23%), CD71-72 (1.23%), IVS-II-654 (1.04%), -28 (0.37%), CD43 (0.19%), -29 (0.18%) and βE (0.09%). In the α and β composite thalassemia there were 12 genotypes. The -α/αα was the most common genotype co-existed with β-thalassemia (1.70%), followed by the -α /αα genotype (0.94%).

CONCLUSIONThe data of this study provide the frequency and the spectrum of thalassemia gene mutations in the sanya area of Hainan province, which can contribute to set up the strategies for the prevention and control of thalassemia in this area.

OBJECTIVE: To investigate the gene mutation types and gene carrying rate of common thalassemia in patients with thalassemia in Quanzhou, and to analyze its molecular epidemiological characteristics in Quanzhou. METHODS: 546 patients with thalassemia diagnosed at the first hospital of Quanzhou from January 2017 to October 2018 were collected and retrospectively analyzed for their types of mutations and carrier rates. RESULTS: Among the 4226 samples submitted, 546 positive samples were detected, the total carrying rate of the thalassaemia genes was 12.92%; the carrier rate of α-thalassemia was 8.16%; the carrier rate of β-thalassemia was 4.76%; There were more α-thalassemia missing patients than non-deleted patients. The Southeast Asian deletion type (-- /αα) was the most common one, with a composition ratio of 68.98%, which was followed by 22.61% (-α/αα), 2.61% (αα/αα), and 2.32% (αα/αα), 2.32% (αα/αα), 1.16% (-α/αα); 9 types of β-thalassemia gene mutations were detected. The most common three mutations were IVSII-654 (C→T, 42.29%), CD41-42 (-TTCT, 33.83%), CD17 (A→T, 12.94%). 2 cases of --/αα , 1 case of αα/ααα and 1 case of HKαα were detected. CONCLUSION This study shows that the gene carrying rate of thalassemia in Quanzhou is high and has diversity, which can provide some reference for the prevention and control of thalassemia in Quanzhou.
China ; Genotype ; Humans ; Mutation ; Retrospective Studies ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To investigate the gene-carrying rate and genetic types of thalassemia among the couples of child-bearing age in Ding'an, Hainan province. METHODS: A total of 1742 couples at child bearing age in the region were screened for thalassemia by detecting the mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV). If the sample data of either spouse of couples was tested as MCV＜82 fl and /or MCH＜27 pg, both samples of the couple would be further assayed by hemoglobin electrophoresis. Those samples of HbA2 2.5 % or HbA2＞3.5 % were judged as positive in the preliminary screening, then subjected to genetic diagnosis of thalassemia. RESULTS: 478 cases out of 1 742 couples of child bearing age were diagnosed as thalassemia gene mutation, and the gene-carrying rate was 13.72 %. In those carriers, 42 couples were diagnosed with the same type of thalassemia, accounting for 3.67 %. The gene-carrying rate of α-thalassemia, β-thalassemia and αβ-thalassemia was 9.56%, 3.10% and 1.06 % respectively. CONCLUSION The Ding'an area in Hainan Province is an area with high incidence of thalassemia, and the main genotype is α-thalassemia, showing a distribution of local characteristics. The government should make efferts to popularise the screening for thalassemia, so as to effectively prevent the birth of children with thalassemia major.
Erythrocyte Indices ; Genetic Testing ; Heterozygote ; Humans ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To analyze the genotype and hematological characteristics of children with αβ-thalassemia in Shenzhen area of China. METHODS: The erythrocyte parameters and hemoglobin components of the children were determined by blood routine examination and capillary electrophoresis (CE). Reverse dot blot (RDB) -polymerase chain reaction (PCR) was used to determine gene mutations in α- and β-thalassemia children. The Gap-PCR was used to determine the gene deletion of α-thalassemia children，while specimens suspected HKαα were determined with nested PCR. RESULTS: Total of 29 complex genotypes were detected from 74 cases of αβ-thalassemia, among which 1 case was determined as β-thalassemia with αααanti4.2/αα and 5 cases were double heterozygous β-thalassemia combining α-thalassemia with intermediate phenotype. 1 case of β-28/βcap+40-43 double heterozygotes combined with --/αα and the other 62 cases were characterized by light β-thalassemia, 2 cases ofβCAP+40-43/βN with --/αα showed light α-thalassemia. CONCLUSION The genotypes of αβ-thalassemia in Shenzhen area of China are complex and diverse. The common complex genotypes are similar to those of simple β-thalassemia. If the genotype and phenotype are not consistent, the existence of rare genotype should be considered.
Child ; China ; Genotype ; Humans ; Phenotype ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To investigate the genetic carrier rate of thalassemia and its gene mutation types as well as the distribution characteristics among the people in Lingshui Li autonomous county of Hainan province, so as to provide the basis for making the prevention programs of thalassemia in administrative departments. METHODS: Samples were collected from couples undergoing premarital and pregestational screenings, in which the positive ones in preliminary screening were further tested by genetic diagnoses and the genotypes were analyzed. RESULTS: The rate of thalassemia gene carriers was 19.41% （274/1412） of the couples of childbearing age in Lingshui Li autonomous County of Hainan Province. In these carriers,α-thalassemia accounted for 83.21%（228/274）, β-thalassemia for 8.03%（22/274）, and both α-and β-thalassemia gene accounted for 8.76% （28/274）. CONCLUSION The carrying rate of thalassemia gene in population Lingshui Li autonomous county of Hainan province is high, and its distribution has geographical characteristics,the major type is α-thalassemia. Blood screening and genetic diagnosis of thalassemia should be strengthened, and corresponding measures should be taken to reduce its gene frequency.
China ; Genetic Testing ; Genotype ; Heterozygote ; Humans ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To investigate the gene-carrying rate and gene mutation types of α- and β-thalassemia in population of Fujian area and to analyze the differences in hemoglobin A2 (HbA2), mean cell volume (MCV) and mean cell hemoglobin (MCH) between different types of thalassemia, so as to provide the reference basis for screening and classification, genetic diagnosis and counseling about thalassemia. METHODS: Total 1474 samples from different areas of Fujian province were detected for α- and β-thalassemsia genotypes by gap single PCR (GS-PCR) combined with reverse dot blot hybridization (RDB). The detection of peripheral RBC, hemoglobin and primary screening of thalassemia in each set of sample were carried out before test. RESULTS: Among the detected 1474 samples, 704 (47.76%) were diagnosed as α-thalassemia, out of them 416 (28.22%) were diagnosed as α-thalassemia, 267(18.11%) as β-thalassemia, 21 (1.43%) as αβ-thalassemia. The α-thalassemia further was divide into 3 types: silent (5.09%), minor (22.18%) and HbH disease (0.95%), and their MCV, MCH and HbA2 levels were detected. The detection results showed obvious decrease trend with significant difference (P＜0.05). CONCLUSION The gene mutation types of thalassemia display obvious heterogenity in Fujian area. The gene type in α-thalassemia mostly is --/αα, the gene type in β-thalassemia mostly is IVS-Ⅱ-654. Moreover, the sings of anemia in Hb H disease of α-thalassemia are mostly serious, which obviously are different from other types of α-thalassemia.
China ; Genotype ; Hemoglobin A2 ; Humans ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To investigate the gene mutation types and spectrum of α, β-thalassemia in Fuzhou area of China. METHODS: Thalassemia gene screening was performed in the women receiving physical, prenatal, and pre-pregnancy examination, and the patients with suspected thalassemia in our hospital from July 2013 to March 2018.Genotypes of thalassem were detected by Gap-PCR and RDB-PCR. RESULTS: 1042 were positive among 2074 suspected cases with a positive rate of 50.24%; 618 cases were confirmed to be α-thalassemia and with a positive rate of 29.8%; 409 cases were confirmed to be β-thalassemia with a positive rate of 19.72%. 15 cases were confirmed to be α-β complex thalassemia with a positive rate of 0.72%. the --/αα(76.54%) was the most common genotype among α-thalassemia, -α/αα(10.03%) and -α/αα(2.91%) in hot pursuit. In addition, IVS-II-55 (T->G) and IVS-II-119 (-G, +CTCGGCCC) were newly found alpha mutations; the IVS-2-654 (C→T) (40.83%) was the most common genotype among β-thalassemia, CD41-42 (-TCTT) (35.94%) and CD17 (A→T) (9.78%) in hot pursuit. CONCLUSION The genotype of thalassemia in Fuzhou area is highly heterogenic, --/αα is the most common genotype among α-thalassemia, IVS-2-654 (C→T) is the most common genotype among β-thalassemia, Meanwhile, two α-mutation sites are found in this study which were not reported in the Database of Human Hemoglobin Variants and Thalassemias.
China ; Female ; Genotype ; Humans ; Mutation ; Pregnancy ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To determine the frequency of Hong Kong αα (HK αα) gene in α3.7 positive samples among carriers from Fujian area. METHODS: Routine genetic testing for thalassemia was carried out for 10145 patients with positive screening results. Single PCR and two-round nested PCR were utilized to detect HK αα among 507 patients with α3.7/αα and 2 patients for whom electrophoresis showed α3.7, -αSEA and normal α2 alleles. Reverse dot blot test was used for detecting non-deletional α-thalassemia and β-thalassemia variants. RESULTS: Among the 507 patients with α3.7/αα, HK αα was identified in 35 cases, which included 25 HK αα/αα, 5 HK αα/α3.7, 4 HK αα/αα with heterozygous CD41/42 (HBB: c.126_129delCTTT) variant, 1 HK αα/αα with IVS-II-654 (HBB: c.316_197C>T) heterozygous variant. One patient was confirmed to have α3.7/anti4.2 genotype. The two cases with α3.7, -αSEA and normal α2 alleles were confirmed to be HK αα/--SEA. The frequency of HK αα genotype in Fujian area was therefore 7.27% among patients with α3.7 and 0.36% in the general population. CONCLUSION A certain proportion of HK αα has been detected in Fujian area, which will enable more accurate diagnosis and genetic counseling.
Genotype ; Heterozygote ; Hong Kong ; Humans ; alpha-Thalassemia ; beta-Thalassemia

OBJECTIVE: To analyze the genotype of pregnant women with α- and β- thalassemia in Fuzhou area of Fujian province in China. METHODS: Blood routine examination and hemoglobin electrophoresis were performed for pregnant women, and positive samples were examined by gap polymerase chain reaction and reverse dot blot hybridization. RESULTS: 412 cases were diagnosed as α-thalassemia (63.9%); 201 cases were diagnosed as β-thalassemia (31.2%); 32 cases were diagnosed as α and β-composite thalassemia. There were 12 genotypes in α-thalassemia, whose major genotypes were --/αα, α/αα, -α/αα and αα/αα, with carrying rate of 64.32%, 20.14%, 7.77% and 1.94%, respectively. There were 10 genotypes in β- thalassemia, whose major genotypes were CD41-42/N, CD17/N, IVS-II-654/N and -28/N, with carrying rate of 30.84%, 27.86%, 15.92% and 10.45%, respectively. There were 9 genotypes in α and β-composite thalassemia, whose major genotypes were --/αα composited CD41-42/N, -α/αα composited CD41-42/N, --/αα composited CD17/N, with carrying rate of 18.75%, 15.62%, 15.62% respectively. CONCLUSION The major genotypes of pregnant women with α- and β- thalassemia in Fuzhou area of Fujian province in China are --/αα, α/αα, CD41-42/N and CD17/N. Thalassemia screening and prenatal gene diagnosis should be strengthened in Fuzhou area of Fujian province in China.
China ; Female ; Genotype ; Humans ; Mutation ; Pregnancy ; alpha-Thalassemia ; beta-Thalassemia