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Scientific Reports Jun 2022Thalassemia is a group of common hereditary anemias that cause significant morbidity and mortality worldwide. However, precisely diagnosing thalassemia, especially rare...
Thalassemia is a group of common hereditary anemias that cause significant morbidity and mortality worldwide. However, precisely diagnosing thalassemia, especially rare thalassemia variants, is still challenging. Long-range PCR and long-molecule sequencing on the PacBio Sequel II platform utilized in this study could cover the entire HBA1, HBA2 and HBB genes, enabling the diagnosis of most of the common and rare types of thalassemia variants. In this study, 100 cases of suspected thalassemia were subjected to traditional thalassemia testing and third-generation sequencing for thalassemia genetic diagnosis. Compared with traditional diagnostic methods, an additional 10 cases of rare clinically significant variants, including 3 cases of structure variants and 7 cases of single nucleotide variations (SNVs) were identified, of which a case with - α subtype III (- α) was first identified and validated in the Chinese population. Other rare variants of 11.1 kb deletions (- 11.1/αα), triplicate α-globin genes (aaa/αα) and rare SNVs have also been thoroughly detected. The results showed that rare thalassemia variants are not rare but have been misdiagnosed by conventional methods. The results further validated third-generation sequencing as a promising method for rare thalassemia genetic testing.
Topics: Genotype; Humans; Mutation; Sequence Analysis, DNA; alpha-Globins; alpha-Thalassemia; beta-Thalassemia
PubMed: 35701592
DOI: 10.1038/s41598-022-14038-8 -
Medicine Mar 2022There is no information concerning the prevalence of thalassemia among pregnant women in Hubei Province currently. This study is aimed to explore the prevalence of α-... (Observational Study)
Observational Study
There is no information concerning the prevalence of thalassemia among pregnant women in Hubei Province currently. This study is aimed to explore the prevalence of α- and β-thalassemia genotypes among pregnant women in Hubei Province, and to explore the clinically applicable screening approach, as well as to investigate the pregnancy outcomes of α- and β-thalassemia carriers.Pregnant participants were recruited from 4 hospitals for the screening of α- and β-thalassemia mutations in Hubei Province. Polymerase Chain Reaction and flow cytometry methods were used to examine α- and β-thalassemia mutations. The hematological parameters and pregnancy outcomes of α- and β-thalassemia carriers were obtained from the hospital information system. The chi-square tests were used to evaluate the difference in hematological parameters between pregnant thalassemia carriers and the control group.Among 11,875 participants, 414 (3.49%) were confirmed with α-thalassemia carriers, 228 (1.92%) were confirmed with β-thalassemia carriers, and 3 (0.03%) were confirmed with both α- and β-thalassemia carriers. The frequency of -α3.7 accounted for 2.05% and it was the most frequent genotype of α-thalassemia; the proportion of IVS-II-654 was 0.85% and it was the most frequent genotype of β-thalassemia in Hubei Province. Furthermore, the proportion of patients with low mean corpuscular volume (MCV) or mean cell hemoglobin (MCH) values was accounted for 36.64% and 93.97% among α-thalassemia and β-thalassemia carriers, respectively. And participants with normal MCV and MCH values were accounted for 95.07% among non-thalassemia participants. High prevalence of pregnancy-induced diabetes (16.97%), preterm birth (9.96%), pregnancy-induced hypertension (8.12%), and low birth weight (5.90%) were observed among pregnant thalassemia carriers.MCV and MCH values were suggested to apply on the preliminary screening of pregnant β-thalassemia; however, it's unpractical on that of α-thalassemia. Furthermore, thalassemia carriers might have a high risk of negative pregnancy outcomes. These findings could be useful for the preliminary screening of thalassemia and perinatal care for the pregnant thalassemia carriers.
Topics: China; Diabetes, Gestational; Female; Genotype; Hemoglobins; Humans; Hypertension, Pregnancy-Induced; Infant, Low Birth Weight; Infant, Newborn; Male; Polymerase Chain Reaction; Pregnancy; Pregnancy Complications, Hematologic; Pregnant Women; Premature Birth; Prevalence; alpha-Thalassemia; beta-Thalassemia
PubMed: 35244037
DOI: 10.1097/MD.0000000000028790 -
Oncology Letters May 2018Sarcoma is a rare and heterogeneous type of cancer with an early mean onset age and a poor prognosis. However, its genetic basis remains unclear. A series of recent... (Review)
Review
Sarcoma is a rare and heterogeneous type of cancer with an early mean onset age and a poor prognosis. However, its genetic basis remains unclear. A series of recent genomic studies in sarcomas have identified the occurrence of mutations in the α-thalassemia/mental retardation syndrome X-linked (ATRX) gene. The ATRX protein belongs to the SWI/SNF family of chromatin remodeling proteins, which are frequently associated with α-thalassemia syndrome. Cancer cells depend on telomerase or the alternative lengthening of telomeres (ALT) pathway to overcome replicative programmed mortality. Loss of ATRX is associated with ALT in sarcoma. In the present review, recent whole genome and/or whole exome genomic studies are summarized. In addition ATRX immunohistochemistry and ALT fluorescence hybridization in sarcomas of various subtypes and at diverse sites, including osteosarcoma, leiomyosarcoma, liposarcoma, angiosarcoma and chondrosarcoma are evaluated. The present review involves certain studies associated with the molecular mechanisms underlying the loss of ATRX controlling the activation of ALT in sarcomas. Identification of the loss of ATRX and ALT in sarcomas may provide novel methods for the treatment of aggressive sarcomas.
PubMed: 29725455
DOI: 10.3892/ol.2018.8318 -
International Journal of Molecular... Nov 2023The dADD1 and dXNP proteins are orthologues of the ADD and SNF2 domains of the vertebrate ATRX (Alpha-Thalassemia with mental Retardation X-related) protein. ATRX plays... (Review)
Review
The dADD1 and dXNP proteins are orthologues of the ADD and SNF2 domains of the vertebrate ATRX (Alpha-Thalassemia with mental Retardation X-related) protein. ATRX plays a role in general molecular processes, such as regulating chromatin status and gene expression, while dADD1 and dXNP have similar functions in the genome. Both ATRX and dADD1/dXNP interact with various protein partners and participate in various regulatory complexes. Disruption of ATRX expression in humans leads to the development of α-thalassemia and cancer, especially glioma. However, the mechanisms that allow ATRX to regulate various cellular processes are poorly understood. Studying the functioning of dADD1/dXNP in the model may contribute to understanding the mechanisms underlying the multifunctional action of ATRX and its connection with various cellular processes. This review provides a brief overview of the currently available information in mammals and regarding the roles of ATRX, dXNP, and dADD1. It discusses possible mechanisms of action of complexes involving these proteins.
Topics: Animals; Humans; alpha-Thalassemia; Chromatin; DNA Helicases; Drosophila; Drosophila melanogaster; Drosophila Proteins; Mammals; X-linked Nuclear Protein
PubMed: 38003676
DOI: 10.3390/ijms242216486 -
BioRxiv : the Preprint Server For... May 2024Alpha-thalassemia is an autosomal recessive disease with increasing worldwide prevalence. The molecular basis is due to mutation or deletion of one or more duplicated...
Alpha-thalassemia is an autosomal recessive disease with increasing worldwide prevalence. The molecular basis is due to mutation or deletion of one or more duplicated α-globin genes, and disease severity is directly related to the number of allelic copies compromised. The most severe form, α-thalassemia major (αTM), results from loss of all four copies of α-globin and has historically resulted in fatality . However, transfusions now enable survival to birth. Postnatally, patients face challenges similar to β-thalassemia, including severe anemia and erythrotoxicity due to imbalance of β-globin and α-globin chains. While curative, hematopoietic stem cell transplantation (HSCT) is limited by donor availability and potential transplant-related complications. Despite progress in genome editing treatments for β-thalassemia, there is no analogous curative option for patients suffering from α-thalassemia. To address this, we designed a novel Cas9/AAV6-mediated genome editing strategy that integrates a functional α-globin gene into the β-globin locus in αTM patient-derived hematopoietic stem and progenitor cells (HSPCs). Incorporation of a truncated erythropoietin receptor transgene into the α-globin integration cassette dramatically increased erythropoietic output from edited HSPCs and led to the most robust production of α-globin, and consequently normal hemoglobin. By directing edited HSPCs toward increased production of clinically relevant RBCs instead of other divergent cell types, this approach has the potential to mitigate the limitations of traditional HSCT for the hemoglobinopathies, including low genome editing and low engraftment rates. These findings support development of a definitive autologous genome editing strategy that may be curative for α-thalassemia.
PubMed: 38766216
DOI: 10.1101/2023.09.01.555926 -
Biomedical and Environmental Sciences :... Oct 2021Thalassemia is a group of genetically heterogeneous diseases characterized by hemolytic anemia. To investigate molecular characteristics of α- and β-thalassemia among...
Thalassemia is a group of genetically heterogeneous diseases characterized by hemolytic anemia. To investigate molecular characteristics of α- and β-thalassemia among young individuals of marriageable age in Guangdong Province, 24,788 subjects with suspected thalassemia were genetically tested for α- and β-thalassemia by Gap-PCR and reverse dot blot during 2018-2019. For suspected rare thalassemia cases, DNA sequencing was performed to identify rare and unknown thalassemia gene mutations. A total of 14,346 thalassemia carriers were detected, including 7,556 cases of α-thalassemia with 25 genotypes and 8 α-gene mutations identified, 5,860 cases of β-thalassemia with 18 genotypes and 18 β-gene mutations identified, and 930 cases of compound α/β-thalassemia. Among them, the frequency of -- deletion was the highest in α-thalassemia (66.01%), followed by -α (17.98%) and -α (8.22%), and the frequency of CD41-42 (-TCTT) mutation was the highest in β-thalassemia (38.38%), followed by IVS-II-654 (C > T) (25.67%), -28 (A > G) (15.76%), and CD17 (10.01%). In addition, 5 rare mutations (--THAI and HKαα, CD113, -90, and CD56) were found in the study population. Our results revealed molecular epidemiological background of α- and β-thalassemia in Guangdong Province, which can support optimization of thalassemia prevention and control strategies. We demonstrated that thalassemia is heterogeneous with significant geographical differences and population specificity.
Topics: Adult; China; Female; Genotype; Humans; Male; Middle Aged; Mutation; Sequence Analysis, DNA; Young Adult; alpha-Thalassemia; beta-Thalassemia
PubMed: 34782049
DOI: 10.3967/bes2021.112 -
Genetics and Molecular Biology 2021Alpha thalassemia is the most common genetic disorder across the world, being the α-3.7 deletion the most frequent mutation. In order to analyze the spectrum and origin...
Alpha thalassemia is the most common genetic disorder across the world, being the α-3.7 deletion the most frequent mutation. In order to analyze the spectrum and origin of alpha thalassemia mutations in Uruguay, we obtained a sample of 168 unrelated outpatients with normal hemoglobin levels with microcytosis and hypochromia from two cities: Montevideo and Salto. The presence of α-thalassemia mutations was investigated by gap-PCR, restriction endonucleases analysis and HBA2 and HBA1 genes sequencing, whereas the alpha-MRE haplotypes were investigated by sequencing. We found 55 individuals (32.7%) with α-thalassemia mutations, 51(30.4%) carrying the -α3.7 deletion, one with the -α4.2 deletion and three having the rare punctual mutation HBA2:c.-59C>T. Regarding alpha-MRE analysis, we observed a significant higher frequency of haplotype D, characteristic of African populations, in the sample with the -α3.7 deletion. These results show that α-thalassemia mutations are an important determinant of microcytosis and hypochromia in Uruguayan patients with microcytosis and hypochromia without anemia, mainly due to the -α3.7 deletion. The alpha-MRE haplotypes and the α-thalassemia mutations spectrum suggest a predominant, but not exclusive, African origin of these mutations in Uruguay.
PubMed: 33769430
DOI: 10.1590/1678-4685-GMB-2020-0399 -
Medeniyet Medical Journal 2021Alpha thalassemia (α-thalassemia) is an autosomal recessive disorder due to the reduction or absence of α globin chain production. Laboratory diagnosis of...
Alpha thalassemia (α-thalassemia) is an autosomal recessive disorder due to the reduction or absence of α globin chain production. Laboratory diagnosis of α-thalassemia requires molecular analysis for the confirmatory diagnosis. A screening test, comprising complete blood count, blood smear and hemoglobin quantification by high performance liquid chromatography and capillary electrophoresis, may not possibly detect all the thalassemia diseases. This review focused on the molecular techniques used to detect α-thalassemia, and the advantages and disadvantages of each technique were highlighted. Multiplex gap-polymerase chain reaction, single-tube multiplex polymerase chain reaction, multiplex ligation-dependent probe amplification, and loop-mediated isothermal amplification were used to detect common deletion of α-thalassemia. Furthermore, the reverse dot blot analysis and a single tube multiplex polymerase chain reaction could detect non-deletion mutation of the α-globin gene. Sanger sequencing is widely used to detect non-deletion mutations of α-thalassemia. Recently, next-generation sequencing was introduced in the diagnosis of both deletion and point mutations of α-thalassemia. Despite the advantages and disadvantages of different techniques, the routine method employed in the laboratory should be based on the facility, expertise, available equipment, and economic conditions.
PubMed: 34915685
DOI: 10.5222/MMJ.2021.14603 -
Frontiers in Genetics 2022There are limited studies on the molecular profile of thalassemia in Hainan, the free trade island in China. Our aim was to reveal the prevalence and molecular mutation...
There are limited studies on the molecular profile of thalassemia in Hainan, the free trade island in China. Our aim was to reveal the prevalence and molecular mutation spectrum of thalassemia in different ethnic groups and regions of Hainan through a large sample study for the first time. A total of 231,596 individuals from 19 cities and counties in Hainan were screened by hematological parameter analysis, and further genetic analysis was performed on individuals with MCV less than 82 fL. Totally, 31,780 (13.72%) subjects were diagnosed as thalassemia carriers. The overall prevalence of α-thalassemia, β-thalassemia, and α+β-thalassemia were 11.04%, 1.48%, and 1.20%, respectively. We further analyzed the molecular profiles of thalassemia in various ethnic groups and mainly compared the difference between Han and Li. The results showed that the frequency of thalassemia in the Li population (47.03%) was much higher than that in Han (9.37%). Except for β-thalassemia (1.31% of Li vs. 1.47% of Han), the frequencies of α-thalassemia (39.59% of Li vs. 7.35% of Han) and α+β-thalassemia (6.13% of Li vs. 0.56% of Han) in the Li were obviously higher than those in Han. The high-frequent genotypes of α-thalassemia in Han were αα/-- (25.55%), -α/αα (22.17%), -α/αα (21.59%), αα/αα (8.93%), and -α/-α (4.17%) and those of Li were -α/αα (17.24%), -α/αα (17.16%), -α/-α (15.09%), αα/αα (9.69%), and αα/-α (8.06%), respectively. The αα/-- was the highest genotype of α-thalassemia in Han but only accounted for 1.87% in Li. For β-thalassemia, the top three high-frequent genotypes in both Han and Li were β/β, β/β, and β/β, but the frequency of β/β in Li (90.96%) was much higher than that in Han (56.32%) and the data reported in other provinces of China. Additionally, the prevalence of thalassemia ranged from 8.16% to 34.35% in Hainan, Wuzhishan, Baoting, Qiongzhong, and Baisha have a higher prevalence than other areas. Our study revealed the characteristics of ethnic and regional differences in the prevalence of thalassemia in the childbearing age population of Hainan for the first time, indicating that the prevalence of thalassemia among Li nationality is the highest in China. Those findings will be useful for genetic counseling and the prevention of thalassemia.
PubMed: 35783269
DOI: 10.3389/fgene.2022.874624