OBJECTIVE: To analyze the correlation between variants in the start codon of the α-globin gene and phenotypes of thalassemia, so as to provide a basis for the diagnosis and prevention of α-thalassemia. METHODS: A retrospective study was conducted on 7 patients diagnosed by Yangjiang People's Hospital and Guangzhou Hybribio Co. Ltd., from June 2019 to October 2022. Routine blood tests and hemoglobin electrophoresis were carried out. Potential variants were identified through polymerase chain reaction (PCR) combined with Reverse dot blotting (RDB), Gap-PCR, and Sanger sequencing. This study has been approved by the Medical Ethics Committee of People's Hospital of Yangjiang (Ethics No: 20240001). RESULTS: For the 7 patients, results of blood routine test of one case was unknown, and that of another was normal. The remaining 5 cases had presented with microcytic hypochromic anemia. The results of hemoglobin electrophoresis showed that one case had normal Hb A and slightly lower Hb A2, whilst another had significantly decreased Hb A and Hb A2, in addition with the appearance of a Hb H band. The content of Hb Bart's in four neonates was ≥ 0.4%. The remaining one case had no result. Genetic testing has identified 4 rare start codon mutations, namely HBA2: c.2delT, HBA2: c.1A>G, HBA2: c.1A>T, and HBA1: c.2T>C. Among these, Patient 1 had harbored compound heterozygous variants of HBA2: c.427T>C (Hb CS) and HBA2: c.2delT. Patient 4 had harbored compound heterozygous variants of HBA2: c.1A>G and Southeast Asian type deletion. CONCLUSION Heterozygotes with HBA start codon variants usually present as silent or mild thalassemia, and the symptoms of anemia may deteriorate when combined with other α-thalassemia variant. The HBA2: c.1A>T start codon variant was unreported previously in China. The detection of start codon variants has helped to clarify the causes of anemia, genetic counseling, and guidance for reproduction.
Humans ; Phenotype ; Codon, Initiator/genetics* ; Female ; Male ; Retrospective Studies ; alpha-Globins/genetics* ; alpha-Thalassemia/genetics* ; Hemoglobin A/genetics* ; Adult ; Mutation

OBJECTIVE: To analyze the hematological characteristics of patients with three common deletional β-thalassemia and concomitant α-thalassemia in Huizhou, Guangdong province. METHODS: A total of 1 335 subjects of childbearing age with hemoglobin F (Hb F) ≥ 5% at the Huizhou First Maternal and Child Health Care Hospital between June 2014 and December 2023 were enrolled as our study cohort. The hematological parameters were determined by blood cell counters and automatic capillary electrophoresis, while liquid phase chip and gap-PCR were employed for the detection of routine thalassemias and the three common deletional β-thalassemia, respectively. The hematological characteristics of patients with the deletional β-thalassemia were analyzed. This study was reviewed and approved by the Ethics Committee of Huizhou First Maternal and Child Health Care Hospital [Ethics No. 20231107(B2)]. RESULTS: A total of 384 cases of the three common deletional β-thalassemia were identified, including 184 cases of Chinese Gγ⁺(Aγδβ)⁰, 191 cases of Southeast Asian hereditary persistence of fetal hemoglobin (SEA-HPFH), and nine cases of Chinese Taiwanese, for a total detection rate of 28.76%. Patients who did not meet the established criteria were excluded from the study, leaving 372 cases. All of which presented with hypochromic microcytic anemia and significantly elevated Hb F. Except for normal or decreasing of Hb A2 levels in patients with Chinese Gγ⁺(Aγδβ)⁰, the levels of Hb A2 in patients with the other two deletional β-thalassemia were increased with different degrees. Differential comparison results showed that significant differences were observed in Hb A2 and Hb F values among the groups of the three common deletional β-thalassemia heterozygotes (P < 0.05). According to the type of gene variation, 180 patients with Chinese Gγ⁺(Aγδβ)⁰ heterozygotes were divided into three groups, including αα/αα, Chinese Gγ⁺(Aγδβ)⁰/β^N (149), -α/αα, Chinese Gγ⁺(Aγδβ)⁰/β^N (14), and --/αα, Chinese Gγ⁺(Aγδβ)⁰/β^N (17). Similarly, 179 patients with SEA-HPFH heterozygotes were divided into three groups, including αα/αα, SEA-HPFH/β^N (150), -α/αα, SEA-HPFH/β^N (12), and --/αα, SEA-HPFH/β^N (17). Differential comparison results showed that the Hb F levels of the Chinese Gγ⁺(Aγδβ)⁰ combined with α⁰-thalassemia group were significantly lower than those of the Chinese Gγ⁺(Aγδβ)⁰ combined with α⁺-thalassemia group and the control group (P < 0.05). The mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and Hb F values of the SEA-HPFH combined with α⁰-thalassemia group were significantly lower than those of the SEA-HPFH combined with α⁺-thalassemia group and the control group (P < 0.05). CONCLUSION The above research results can not only enhance the ability of clinicians to identify deletional β-thalassemia and concomitant α-thal, improve the level of genetic counseling, but also provide data support for the development of deletional β-thalassemia prevention and control programme and the development of prenatal and postnatal care.
Humans ; beta-Thalassemia/complications* ; alpha-Thalassemia/complications* ; Female ; China ; Male ; Adult ; Fetal Hemoglobin/genetics* ; Adolescent ; Young Adult

OBJECTIVE: To explore the clinical phenotype and genetic etiology of a neonate with X-linked alpha-thalassemia mental retardation syndrome (ATR-X) caused by ATRX gene variant, and review related literature on children with ATR-X caused by ATRX gene variants. METHODS: A case of ATR-X neonate who was transferred to the First Affiliated Hospital of Zhengzhou University on February 11, 2022 for poor effect of treatment in the neonatology department of the hospital where he was born for 4 days due to "postnatal slow response, groaning, and cyanosis of the skin for 30 min" was selected as the study subject. 3 mL of peripheral blood was collected from the child and their parents, and genomic DNA was extracted for whole exome sequencing (WES). Sanger sequencing was used to verify the pathogenic gene variations in the child's family. The pathogenicity of genetic variant sites was assessed based on the Standards and Guidelines for the Interpretation of Sequence Variants by American College of Medical Genetics and Genomics (ACMG). The amino acid sequence conservation analysis of relevant variant proteins was conducted by the Universal Protein Resource Database (UniProt) and visual analysis of these variant proteins was performed by Swiss online protein three-dimensional modeling database (SWISS-MODEL). Using keywords such as "ATRX gene" and " X-linked alpha-thalassemia mental retardation syndrome" both in Chinese and English, relevant literature on ATR-X children caused by ATRX gene variants was retrieved from the CNKI, Wanfang Data Knowledge Service Platform, and PubMed databases, and the clinical phenotypes of ATR-X patients reported in the retrieved literature were analyzed. The literature retrieval time was set from the establishment of each database to December 31st, 2023. This study followed the research procedures approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2023-KY-1360-002), and informed consent of clinical study was signed by the guardian of the child. RESULTS: The child in this study presented with symptoms such as delayed response, feeding difficulties accompanied by vomiting, low body temperature, hypotonia in all extremities, apnea, abnormal hearing screening, and a Neonatal Behavioral Neurological Assessment (NBNA) score of 19 (lower than the normal range).Hemoglobin (Hb) electrophoresis suggested the presence of α-thalassemia. The results of WES and Sanger sequencing revealed a hemizygous missense variant c.668G>A (p.C223Y) in exon 9 of the ATRX gene in the child of the study, neither of the parents of the child carried this variant, indicating that it is a de novo variant. Based on the Standards and Guidelines for the Interpretation of Sequence Variants released by ACMG, this gene variant was assessed as pathogenic (PS2+PM2_Supporting+PP3_Strong+PP4_Strong). The results of amino acid sequence analysis revealed that the pathogenic variant site normally encodes cysteine, which is highly conserved among various animal species. This pathogenic variant can lead to alterations in the hydrogen bonding structure of ATRX protein, thereby affecting its structural stability. Based on the clinical manifestations and genetic testing results of the child in this study, a diagnosis of ATR-X syndrome was established Based on the literature retrieval strategy established in this study, 13 relevant articles concerning ATR-X syndrome in children caused by ATRX gene variants were retrieved, including 5 Chinese articles and 8 English articles, involving a total of 311 ATR-X children. Including the child in this study, the total number of ATR-X children reaches 312. All 312 children were male and presented with mental retardation. Among them, 45.8% (143/312) had coexisting α-thalassemia, 45.2% (141/312) had abnormal genital appearance, 44.2% (138/312) had facial malformations, and 30.8% (96/312) had hypotonia. Other phenotypes included microcephaly, skeletal dysplasia, among others. CONCLUSION The ATR-X child in this study exhibit a range of clinical phenotypes, including delayed growth and development, facial malformation, abnormal genital appearance, apnea, vomiting symptoms, among others. The de novo variant of ATRX gene c.668G>A (p.C223Y) was identified as the genetic etiology. This study contributes to the expansion of the clinical phenotype spectrum and genetic variation spectrum of ATR-X children.
Humans ; X-linked Nuclear Protein/genetics* ; alpha-Thalassemia/genetics* ; X-Linked Intellectual Disability/genetics* ; Male ; Infant, Newborn ; Exome Sequencing ; Mutation

OBJECTIVE: To investigate the gene carrier rate and genotype distribution characteristics of thalassemia in the population of Kunming, and compare the differences of red blood cell (RBC) parameters between β⁺ heterozygous carriers, β⁰ heterozygous carriers and healthy population, as well as between different sexes of adults aged 18-45 years. METHODS: A retrospective analysis of 3 195 cases of thalassemia gene screened in the First Affiliated Hospital of Kunming Medical University from April 1, 2020 to March 31, 2022 was performed to detect 21 mutations of β-globin genes which was common in Chinese people using fluorescence PCR melting curve method. Patients with single heterozygous carrying β-thalassemia gene were divided into β⁺ heterozygote group and β⁰ heterozygote group, while the control group consisted of 219 healthy individuals. Four indices, including RBC, hemoglobin (Hb), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were collected from all β heterozygous carriers and 219 healthy people, and compared between β⁺ heterozygote group, β⁰ heterozygote group and control group, as well as between β⁺ heterozygous carriers, β⁰ heterozygous carriers and healthy population of different sexes aged 18-45 years. RESULTS: There were 688 cases confirmed thalassemia gene carriers, accounting for 21.53%. Among them, 322 cases were found to have β-globin gene mutations, including 145 cases of β⁺ heterozygote, 151 cases of β⁰ heterozygote, and 14 cases of β⁺ homozygotes as well as β⁺ and β⁰ dual heterozygotes. Additionally, 12 cases were found to have simultaneous mutation or deletion of β-globin and α-globin. The carrier rate of CD26 G>A mutation in β⁺ thalassemia was the highest, accounting for 57.9%, while in β⁰ thalassemia CD17 A>T was the highest, accounting for 46.4%. The erythrocyte parameters of 296 β heterozygous mutation carriers were compared with the normal reference interval, and it was found that 218 cases with RBC value greater than the highest value of reference interval, while 105, 281, and 269 cases with Hb, MCV, and MCH value less than the lowest value of reference interval, respectively. There were significant differences in the 4 erythrocyte parameters between β⁺ heterozygotes, β⁰ heterozygotes and healthy individuals (all P < 0.001), and further comparison between different sexes also showed significant differences (all P < 0.001). CONCLUSIONS The carrier rates of thalassemia gene and β-thalassemia heterozygote are both at high level in Kunming, and there are significant differences in the erythrocyte parameters between β⁺ heterozygous carriers, β⁰ heterozygous carriers and healthy individuals. When genetic counseling, it is necessary to inform and strengthen screening among adults of marriageable age to prevent birth of children with severe thalassemia.
Humans ; beta-Thalassemia/blood* ; Adult ; Heterozygote ; Male ; Female ; beta-Globins/genetics* ; Retrospective Studies ; Middle Aged ; Mutation ; Adolescent ; Genotype ; Erythrocytes ; Erythrocyte Indices ; Young Adult ; China ; Genetic Testing ; Asian People/genetics*

OBJECTIVE: To investigate the common genotypes and distribution characteristics of thalassemia in Guiyang region, and preliminarily analyze the rare mutations of globin genes in this area. METHODS: A total of 9 334 individuals who came to our hospital for thalassemia screening from June 2016 to February 2023 were included in this study. They were examined for common thalassemia mutations using PCR-based flow-through hybridization technology. Meanwhile, rare and unknown mutations were detected by Sanger sequencing. RESULTS: Among the 9 334 cases, 895 positive cases of common thalassemia were detected, with a positive rate of 9.59%. Among the positive samples, 565 cases (63.13%) were confirmed to be α thalassemia, of which the most common genotypes were αα/-α^3.7 (46.37%), followed by αα/--^SEA(26.55%) and αα/-α^4.2(10.62%); 310 cases (34.64%) were diagnosed as β thalassemia, with β^CD17/β^N (39.35%) being the most frequent genotype, followed by β^CD41-42 /β^N (31.29%) and β ^IVS-II-654/ β^N (12.90%). There were 20 cases (2.23%) of αβ complex thalassemia, mainly being αα/-α^3.7 combined with β^CD17 /β^N . Additionally, 8 cases of rare globin gene mutations were found by Sanger sequencing, including 7 mutation types. Among them, HBB: c. -137C> T (-87 C>T) was reported for the first time in Guizhou; HBA1 : c.*29C>T and HBB : c. 93-50C>T (IVS I-81C>T) were new mutations that had not been recorded in either the HbVar or IthaGenes database. CONCLUSION Guiyang region has a high incidence of thalassemia mutations, and these mutations are diverse and complex. Analyzing gene mutation types of thalassemia in this area can contribute to the prevention of the birth of children with severe thalassemia.
Humans ; Genotype ; Mutation ; beta-Thalassemia/genetics* ; alpha-Thalassemia/genetics* ; Thalassemia/epidemiology* ; Genetic Testing ; China/epidemiology* ; Male ; Female

OBJECTIVE: To explore the expression and function of microRNA-144 (miR-144) in β-thalassemia (β-thal). METHODS: The expression of miR-144 during the differentiation of murine erythroleukemia (MEL) cells and mouse embryonic liver-derived erythroid precursor cells was analyzed by real-time fluorescence quantitative PCR (qRT-PCR); The expression levels of miR-144 in peripheral blood and day-14.5 embryonic hepatocytes of wild-type (WT) and β-thal mice, as well as the expression levels of miR-144 in peripheral blood of β-thal patients, was also measured by qRT-PCR. The proportion of Ter119 and CD71 double positive cells in peripheral blood of mild and severe β-thal mice was analyzed by flow cytometry, and the expression levels of miR-144 in the peripheral blood of mild and severe β-thal mice and patients were compared; Bone marrow nucleated erythrocytes from WT mice and β-thal mice were sorted and the expression levels of miR-144 potential target genes were analyzed by gene chip. RESULTS: The expression levels of miR-144 were gradually increased during the directed differentiation of mouse MEL cells and embryonic hepatocytes to the erythroid lineage (r _MEL=0.97, r _{embryonic hepatocytes}=0.86); Compared with WT mice, the expression levels of miR-144 in peripheral blood and 14.5-day embryonic hepatocytes of β-thal mice were significantly increased (P < 0.05); Compared with healthy controls, the patients with β-thal showed an increased expression levels of miR-144 in peripheral blood (P < 0.05). Compared with mice and humans with mild β-thal, the expression levels of miR-144 in peripheral blood of those with severe β-thal were significantly increased (P < 0.05). The expressions of potential target genes of miR-144 in nucleated erythroid cells of the β-thal mice were significantly reduced compared to the WT group. CONCLUSION The expression level of miR-144 gradually increases in erythroid development, and compared with mild β-thal patients, the expression level of miR-144 in the peripheral blood is higher in severe β-thal patients. MiR-144 is expected to be an auxiliary diagnostic indicator for β-thal in clinical practice.
MicroRNAs/metabolism* ; beta-Thalassemia/genetics* ; Animals ; Mice ; Humans ; Cell Differentiation ; Hepatocytes

OBJECTIVE: To analyze the distribution of thalassemia (referred to as "thalassemia") gene variant types in the population of the Wuhan area, aiming to provide a genetic basis for the precise prevention and control as well as clinical diagnosis of thalassemia in the Wuhan region. METHODS: In this study, 2 133 suspected thalassemia patients and individuals undergoing prenatal screening who visited the Department of Hematology, Obstetrics and Gynecology, Reproductive Medicine, Pediatrics, and Neurology at Wuhan First Hospital from October 2022 to October 2024 were selected as the research subjects. Peripheral blood samples were collected from the patients. The common 27 thalassemia genotypes of α- and β-thalassemia were initially screened using fluorescence PCR melting curve analysis technology. For samples where the fluorescence PCR melting curve results indicated unknown variants or where the clinical phenotype was inconsistent with the common genotypes, Sanger sequencing technology was used for review and verification. RESULTS: Among the 2 133 specimens analyzed, common thalassemia gene variants were detected in 210 cases (9.85%, 210/2 133). A total of 156 cases (8.05%, 156/1 938) of thalassemia gene variants were detected in females and 54 cases (27.69%, 54/195) in males. A total of 94 cases (4.41%, 94/2 133) of α-thalassemia were detected, including 46 cases (2.16%, 46/2 133) of silent α-thalassemia, 47 cases (2.20%, 47/2 133) of mild α-thalassemia, and 1 case (0.05%, 1/2 133) of intermediate α-thalassemia. Additionally, 111 cases of β-thalassemia were identified (5.20%, 111/2 133), including 51 cases of β/β⁺ thalassemia (2.39%, 51/2 133), 59 cases of β/β⁰ thalassemia (2.77%, 59/2 133), and 1 case of β⁺/HbE thalassemia (0.05%, 1/2 133). αβ-composite thalassemia gene variants were detected in 5 cases (0.23%, 5/2 133), including 1 complex variant with a genotype of --^SEA/αα combined with CD41-42 (-TTCT) and 29(A>G), representing a heterozygous variant of three genotypes. Rare globin gene variants were detected in 3 cases, including HBB:c.60C>T, HBB:c.-146G>T, and HBA2:c.*12G>A. CONCLUSION The Wuhan region exhibits a relatively high prevalence of thalassemia genes with notable gender disparities. While maintaining focus on thalassemia screening for females, enhanced males screening efforts and genetic counseling should be implemented in future prevention programs.
Humans ; Female ; Male ; Genotype ; beta-Thalassemia/genetics* ; China ; Thalassemia/genetics* ; alpha-Thalassemia/genetics* ; Genetic Variation

OBJECTIVE: To determine the carrier rate for thalassemia mutations in the ethnic Miao population of Qianxinan Prefecture. METHODS: Ethnic Miao people suspected for thalassemia trait at the People's Hospital of Qianxinan Prefecture, Guizhou Province between November 2020 to September 2024 were selected as the study subjects. Gap-PCR technology combined with high-throughput sequencing was used to screen a total of 666 individuals. ArcMap v10.8.2 was used to create a spatial distribution map of thalassemia based on the screening results. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2016-01). RESULTS: In total 254 positive cases were detected, with an overall positive rate of 38.14%. Among these, 173 cases were α-thalassemia (25.98%), 77 cases were β-thalassemia (11.56%), and 4 cases were αβ compound thalassemia (0.60%). The most common genotypes for α-thalassemia were αα/--^SEA (positive rate = 10.06%, accounting for 38.73%), αα/-α^3.7 (positive rate = 8.86%, accounting for 34.10%), and α^CSα/αα (positive rate = 4.95%, accounting for 19.08%). The most common genotypes for β-thalassemia were β^41/42(-TTCT)/β^A (positive rate = 5.11%, accounting for 44.16%) and β^{17 (A>T)}/β^A(positive rate = 4.20%, accounting for 36.36%), with these two genotypes accounting for as much as 80.52%. The spatial distribution map indicated that the highest overall detection rate of thalassemia and α-thalassemia in the Miao population of Qianxinan Prefecture was in Xingyi City. The highest detection rate of β-thalassemia was in Zhenfeng County, and the highest detection rate of αβ compound thalassemia was in Wangmo County. CONCLUSION The detection rate of thalassemia among the ethnic Miaos from Qianxinan Prefecture is relatively high, which primarily consisted of α-thalassemia. Regular monitoring and educational outreach should be conducted.
Humans ; China/ethnology* ; Female ; Male ; Genetic Testing ; Adult ; alpha-Thalassemia/genetics* ; Thalassemia/ethnology* ; Ethnicity/genetics* ; Genotype ; beta-Thalassemia/ethnology* ; Adolescent ; Mutation ; Middle Aged ; Child ; Asian People/genetics* ; Young Adult

OBJECTIVE: To study the molecular epidemiology of thalassemia in Jiaxing area of Zhejiang province and provide a basis for prenatal diagnosis, genetic counseling and prevention and control of birth defects. METHODS: A total of 24 003 pregnant women who presented at the Jiaxing Maternal and Child Health Care Hospital from April 2017 to September 2021 were enrolled. Capillary hemoglobin electrophoresis in combination with routine blood test were used for primary screening for carriers of thalassemia-associated mutations, and those with positive results were subjected to fluorescence quantitative PCR assay. Prenatal diagnosis was provided for couples with a risk of giving birth to children with intermediate or severe thalassemia. RESULTS: Among the 24 003 pregnant women, 1 211 cases were suspected as carriers of thalassemia-associated mutations, among whom 443 (36.58%) were confirmed by genetic testing. Among these, carriers of α-, β- and α-complex β-globin gene mutations have accounted for 27.31% (121/443), 70.65% (313/443) and 2.04% (9/443), respectively. The result of prenatal diagnosis for an at-risk couple was --SEA/αCSα, and the fetus was predicted to have intermediate or severe thalassemia. Termination of the pregnancy was recommended. CONCLUSION Hemoglobin electrophoresis combined with routine blood test during pregnancy may be used as a preliminary screening measure for carriers of thalassemia-associated variants. Combined with genetic testing, this will be of great significance for the control of thalassemia in this region.
Female ; Humans ; Pregnancy ; Electrophoresis, Capillary ; Genetic Counseling ; Genetic Testing ; Mutation ; Prenatal Diagnosis ; Thalassemia/genetics*

OBJECTIVE: To explore the carrier rate, genotype and phenotype of α-thalassemia fusion gene in Huadu district of Guangzhou, Guangdong province of China, and provide data reference for the prevention and control of thalassemia. METHODS: A total of 10 769 samples who were screened for thalassemia in Maternal and Child Health Hospital of Huadu District from July 2019 to November 2020 were analyzed retrospectively. Blood cell analysis and hemoglobin (Hb) electrophoresis were performed. Thalassemia genes were analyzed by gap-PCR and PCR-reverse dot blot hybridization (PCR-RDB). RESULTS: A total of 9 cases with α-thalassemia fusion gene were detected in 10 769 samples (0.08%). There were 7 cases with fusion gene heterozygote, 1 case with compound of α-thalassemia fusion gene and Hb G-Honolulu, 1 case with compound of α-thalassemia fusion gene and Hb QS. The MCV results of 4 samples of blood cell analysis were within the reference range, the Hb A2 value of 1 case was decreased, and there were no other abnormalities found. CONCLUSION The α-thalassemia fusion gene is common in Huadu district of Guangzhou, and heterozygotes are more common, and current screening methods easily lead to misdiagnosis.
Humans ; alpha-Thalassemia/genetics* ; Retrospective Studies ; beta-Thalassemia/genetics* ; Genotype ; Phenotype ; Heterozygote ; China ; Mutation