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1.
Am J Case Rep ; 25: e943560, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38725231

ABSTRACT

BACKGROUND Thalassemia and hemoglobin (Hb) variants are the most common hereditary red blood cell disorders worldwide. Alpha-thalassemia and alpha-globin variants are caused by mutations of the alpha-globin genes (HBA2 and HBA1), resulting in impaired alpha-globin production and structurally abnormal globin, respectively. Clinical severity of alpha-thalassemia correlates with the number of affected alpha-globin genes, yielding a spectrum of clinical manifestations from mild to severe anemia. Routine diagnosis involves Hb analysis and PCR-based methods, yet identifying rare variants necessitates comprehensive clinical and hematologic laboratory data. The knowledge of phenotype and genotype correlation is useful for genetic counseling and treatment planning. CASE REPORT A 59-year-old Thai woman presented with chronic anemia. Her baseline Hb level ranged between 8.0 and 9.0 g/dL, with no history of transfusion. Physical examination showed mild pallor, without enlarged liver and spleen. Laboratory investigations showed microcytic, hypochromic anemia and abnormal Hb peak by Hb analysis (retention time 4.58 min by HPLC method). Common alpha-globin gene deletions, including the Southeast-Asian/Thai 3.7 kb and 4.2 kb deletions were tested using gap-PCR, with none of these deletions detected. Direct DNA sequencing revealed a compound heterozygosity of Hb Jax (HBA2: c.44G>C) and Hb Constant Spring (HBA2: c.427T>C). CONCLUSIONS Compound heterozygosity of Hb Jax and Hb Constant Spring results in microcytic anemia. Hb Jax can be identified by Hb analysis, and diagnosis can be confirmed by direct DNA sequencing method. Coinheritance of Hb Jax and alpha-globin variants should be considered in cases with microcytic anemia and a specific Hb peak seen in Hb chromatogram.


Subject(s)
Anemia, Hypochromic , Hemoglobins, Abnormal , Humans , Female , Hemoglobins, Abnormal/genetics , Middle Aged , Anemia, Hypochromic/genetics , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , alpha-Globins/genetics
2.
BMC Pediatr ; 24(1): 330, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38741052

ABSTRACT

BACKGROUND: Thalassemias represent some of the most common monogenic diseases worldwide and are caused by variations in human hemoglobin genes which disrupt the balance of synthesis between the alpha and beta globin chains. Thalassemia gene detection technology is the gold standard to achieve accurate detection of thalassemia, but in clinical practice, most of the tests are only for common genotypes, which can easily lead to missing or misdiagnosis of rare thalassemia genotypes. CASE PRESENTATION: We present the case of an 18-year-old Chinese female with abnormal values of routine hematological indices who was admitted for genetic screening for thalassemia. Genomic DNA was extracted and used for the genetic assays. Gap polymerase chain reaction and agarose gel electrophoresis were performed to detect HBA gene deletions, while PCR-reverse dot blot hybridization was used to detect point mutations in the HBA and HBB genes. Next-generation sequencing and third-generation sequencing (TGS) were used to identify known and potentially novel genotypes of thalassemia. We identified a novel complex variant αHb WestmeadαHb Westmeadαanti3.7/-α3.7 in a patient with rare alpha-thalassemia. CONCLUSIONS: Our study identified a novel complex variant that expands the thalassemia gene variants spectrum. Meanwhile, the study suggests that TGS could effectively improve the specificity of thalassemia gene detection, and has promising potential for the discovery of novel thalassemia genotypes, which could also improve the accuracy of genetic counseling. Couples who are thalassemia carriers have the opportunity to reduce their risk of having a child with thalassemia.


Subject(s)
alpha-Thalassemia , Humans , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Female , Adolescent , High-Throughput Nucleotide Sequencing , Genotype , Genetic Testing/methods , Point Mutation , Hemoglobins, Abnormal/genetics
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(6): 669-676, 2024 Jun 10.
Article in Chinese | MEDLINE | ID: mdl-38818550

ABSTRACT

α-thalassemia is a type of microcytic hypochromic anemia caused by variants of alpha-globin gene, and is one of the most common monogenic disorders in southern China. The population screening model based on hematologic phenotype has achieved great results in areas with high incidence of thalassemia. However, with the continuous decline of the cost of genetic testing and implementation of screening programs for thalassemia gene carriers, more variants in the alpha-globin gene have been discovered, which also brings great challenges to clinical genetic counseling. From the perspective of alpha-globin genetic analysis, this consensus has discussed the contents of pre- and post-test genetic counseling, with an aim to provide standardized guidance for clinicians.


Subject(s)
Genetic Counseling , Genetic Testing , alpha-Thalassemia , Humans , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , alpha-Globins/genetics , Consensus
4.
Taiwan J Obstet Gynecol ; 63(3): 375-380, 2024 May.
Article in English | MEDLINE | ID: mdl-38802201

ABSTRACT

OBJECTIVES: α-thalassemia is an autosomal recessive monogenic blood disorder, affecting up to 5% of the world's population. The occurrence rate of the disease in Vietnam varies up to up to 51.5%, with high rate of mutation carriers, of couples consisting of two carriers at risk of bearing a child with fetal Hb Bart, which can develop into hydrops fetalis syndrome, threatening the well-being of the mother and the child. Our study aims to facilitate birth of healthy/asymptomatic children of α-thalassemia carrier couples who received reproductive service at our centre during the period of 2019-2022. MATERIALS AND METHODS: 89 couples at risks of having α-thalassemia offsprings requested IVF procedures and PGD at Post Hospital during 2019-2022 were recruited for investigation. Couple and additional family members' peripheral blood samples of couples and additional family members were subjected to haemoglobin electrophoresis, DNA extraction for α-thalassemia gene mutation detection and STRs linkage analysis. Data were observed and analysed on GeneMarker software. RESULTS: 91 cycles of PGD for α-thalassemia were carried out for 89 couples. α-thalassemia large deletion (--SEA/αα) was the most common mutation identified in 88 couples, in which 4 cases also carried ß-thalassemia point mutations. Combining results of PGS and PGD, 278/424 amplified embryos were transferable (HBA-mutation free or carriers of single heterozygous HBA mutation, without chromosomal abnormality). 64/89 couples have been transferred with the embryos (prioritizing mutation free ones over carriers), resulting in the birth of 36 α-thalassemia disease-free children, 17 ongoing pregnancies, and 11 with miscarriages. CONCLUSION: Successful application of microsatellite-based method in PGD facilitated the birth of 36 healthy children and 17 ongoing pregnancies for 53/64 couples with embryo-transferred. All resulted clinical births displayed confirmation results in line with the PGD results, thus demonstrating the feasibility and credibility of the use of STR markers in PGD.


Subject(s)
Microsatellite Repeats , Preimplantation Diagnosis , alpha-Thalassemia , Humans , Preimplantation Diagnosis/methods , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Female , Microsatellite Repeats/genetics , Pregnancy , Male , Adult , Vietnam , Heterozygote , Mutation , Fertilization in Vitro/methods
5.
Sci Rep ; 14(1): 8894, 2024 04 17.
Article in English | MEDLINE | ID: mdl-38632453

ABSTRACT

To assess the diagnostic performance of three cardiothoracic (CT) ratio techniques, including diameter, circumference, and area, for predicting hemoglobin (Hb) Bart's disease between 17 and 22 weeks' gestation, and to create a multivariable scoring system using multiple ultrasound markers. Before invasive testing, three CT ratio techniques and other ultrasound markers were obtained in 151 singleton pregnancies at risk of Hb Bart's disease. CT diameter ratio demonstrated the highest sensitivity among the other techniques. Significant predictors included CT diameter ratio > 0.5, middle cerebral artery-peak systolic velocity (MCA-PSV) > 1.5 multiples of the median, and placental thickness > 3 cm. MCA-PSV exhibited the highest sensitivity (97.8%) in predicting affected fetuses. A multivariable scoring achieved excellent sensitivity (100%) and specificity (84.9%) for disease prediction. CT diameter ratio exhibited slightly outperforming the other techniques. Increased MCA-PSV was the most valuable ultrasound marker. Multivariable scoring surpassed single-parameter analysis in predictive capabilities.


Subject(s)
Hemoglobins, Abnormal , alpha-Thalassemia , Pregnancy , Female , Humans , Hydrops Fetalis , Placenta/diagnostic imaging , Ultrasonography, Prenatal/methods , alpha-Thalassemia/diagnosis , Biomarkers
6.
Hematology ; 29(1): 2339559, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38626234

ABSTRACT

OBJECTIVES: In clinical practice, the majority of α-thalassaemia cases arise from deletions of the α-globin genes. However, a subset of cases is attributed to rare haemoglobin variants, which can manifest with borderline or normal screening results, potentially leading to missed diagnoses in clinical practice. METHODS: Blood samples were collected from family members and underwent haematological, DNA and RNA analysis. RESULTS: The five-month-old proband presented a haematological phenotype consistent with Hb H disease. The mother's haematology profile was consistent with an α-thalassaemia carrier, while the father exhibited a borderline reduction in MCV and MCH. MALDI-TOF identified an abnormal α-chain in the proband. DNA analysis revealed a novel α-globin variant (HBA2:c.175C>A, α58His>Asn, Hb DG-Nancheng) affecting the distal histidine in the family. The father and the mother had α-genotype of --SEA/αα and αDG-Nanchengα/αα, respectively; while the proband inherited both mutant alleles (--SEA/αDG-Nanchengα). Sequencing of cDNA from HBA2 gene identified an equal ratio of normal and mutant alleles. CONCLUSION: This rare case highlighted the importance of identifying rare haemoglobin variant during prenatal screening. The clinical and genetic data provides useful information on the pathogenicity of this variant and further insight into the role of distal histidine residue of α-globin.


Subject(s)
Hemoglobins, Abnormal , alpha-Thalassemia , Female , Humans , Infant , Pregnancy , alpha-Globins/genetics , alpha-Thalassemia/diagnosis , alpha-Thalassemia/genetics , China , Hemoglobins, Abnormal/genetics , Histidine/genetics , Mutation
7.
Hemoglobin ; 48(2): 129-132, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38626925

ABSTRACT

Alpha and Beta Thalassemia are autosomal recessive anemias that cause significant morbidity and mortality worldwide, especially in the Middle East and North Africa (MENA) region where carrier rates reach up to 50%. We report the case of two siblings of Palestinian origin born who presented to our tertiary healthcare center for the management of severe transfusion dependent hemolytic anemia. Before presentation to our center, the siblings were screened for a-thalassemia using the Alpha-globin StripAssay. They were found to carry the α2 polyA-1 [AATAAA > AATAAG] mutation in the heterozygous form, which was insufficient to make a diagnosis. No pathogenic variants were detected on Sanger sequencing of the HBB gene. Full sequencing of the a-gene revealed compound heterozygous variants (HBA1:c.119_121delCCA and the previously detected HBA2:c.*+94A > G Poly A [A->G]) with trans inheritance. This report highlights the impact of non-deletional mutations on α-globin chain stability. The compound heterozygosity of a rare α-globin chain pathogenic variant with a polyadenylation mutation in the probands leads to clinically severe a-thalassemia. Due to the high carrier status, the identification of rare mutations through routine screening techniques in our populations may be insufficient. Ongoing collaboration among hematologists, medical geneticists, and counselors is crucial for phenotypic-genotypic correlation and assessment of adequate genetic testing schemes.


Subject(s)
Hemoglobins, Abnormal , Siblings , alpha-Globins , Female , Humans , Male , alpha-Globins/genetics , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Arabs/genetics , Blood Transfusion , Hemoglobins, Abnormal/genetics , Heterozygote , Mutation , Child, Preschool , Child
8.
Hemoglobin ; 48(2): 133-137, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38632978

ABSTRACT

The first identification of a novel α1-Globin variant, Hb Ormylia in 11 Greeks originating from a small village, Ormylia, Chalkidiki, Greece is reported. The new genetic variant leads to the production of a hemoglobin variant that can be identified and quantified by High-Performance Liquid Chromatography. Capillary and classic electrophoresis were not informative. Direct DNA sequencing revealed a new mutation C > G mutation at codon 21 of α1 gene (His > Gln). The new variant has been named Hb Ormylia and this is the first description of this genetic variant of α1 gene in the literature.


Subject(s)
Hemoglobins, Abnormal , alpha-Globins , Adult , Female , Humans , Male , Middle Aged , alpha-Globins/genetics , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Amino Acid Substitution , Greece , Hemoglobins, Abnormal/genetics , Mutation
9.
BMJ Case Rep ; 17(3)2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38514166

ABSTRACT

A term baby presented with cholestatic jaundice since birth. She was diagnosed as gestational alloimmune liver disease-neonatal haemochromatosis (GALD-NH) on evaluation. The baby received intravenous immunoglobulin (IVIG) and recovered gradually from the illness. She was also diagnosed with alpha thalassaemia during the course of evaluation, confirmed by genetic testing. NH is a very rare disorder that results in fetal loss or neonatal death due to liver failure. NH is now known to be a phenotypic expression of GALD. Worldwide, NH is seen in less than one in a million pregnancies. The mortality rate of GALD has traditionally been around 80% with almost all babies needing liver transplantation, with advent of maternal and neonatal IVIG treatment, this has reduced significantly. There is no reported case of GALD-NH treated successfully with IVIG from India. Here, we report an interesting case of GALD-NH with alpha thalassaemia.


Subject(s)
Fetal Diseases , Hemochromatosis , Infant, Newborn, Diseases , Liver Failure , alpha-Thalassemia , Pregnancy , Infant, Newborn , Female , Humans , Immunoglobulins, Intravenous/therapeutic use , alpha-Thalassemia/complications , alpha-Thalassemia/diagnosis , Hemochromatosis/complications , Hemochromatosis/diagnosis
10.
Ann Clin Lab Sci ; 54(1): 114-117, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38514054

ABSTRACT

Platelet count increases are typically a reactionary response to one of a variety of pathophysiological events. We present here a case of microcytic hypochromic red blood cells and thrombocytosis in an adolescent female that we have monitored for three years. The patient was positive for alpha thalassemia trait; negative for mutation in Janus kinase 2, calreticulin, or myeloproliferative leukemia virus oncogene; and negative for reactive causes of thrombocytosis. Noticeably, a variant in atypical chemokine receptor 1 (ACKR1) (c.-67T>C, rs2814778) was found to be homozygous. Accordingly, the case was diagnosed as idiopathic thrombocytosis, and treatment was given to restore platelet levels to normal. Our findings highlight the possibility of an unknown association between alpha thalassemia trait and idiopathic thrombocytosis in the presence of ACKR1 mutation, which could be implicated in disease pathogenesis.


Subject(s)
Thrombocytosis , alpha-Thalassemia , Adolescent , Humans , Female , alpha-Thalassemia/diagnosis , Thrombocytosis/complications , Thrombocytosis/genetics , Thrombocytosis/diagnosis , Platelet Count , Blood Platelets , Diagnosis, Differential
11.
PeerJ ; 12: e17054, 2024.
Article in English | MEDLINE | ID: mdl-38436007

ABSTRACT

Homozygous α0-thalassemia (SEA deletion) or Hb Bart's hydrops fetalis syndrome is a significant public health issue in Thailand and Southeast Asia. A prevention and control program has been implemented in this region. This study focuses on retrospective laboratory data collected between January 2021 and April 2023 at a single center. Additionally, we developed a low-cost LAMP-turbidimetric assay to propose in the screening strategy. A total of 3,623 samples underwent screening tests (MCV, MCH, and DCIP), including 1,658 couple screenings (84.25%) and 310 single pregnant screenings (15.75%). Negative screenings, which did not require further investigation, were found in 75.51% for couple screenings and 46.58% for single pregnant screenings. At hemoglobin (Hb) analysis identified 129 couples which had fetuses at risk of severe thalassemia, whereas molecular analysis during the retrospective period revealed 210 samples with different genotypes. These remaining samples were validated using the low-cost LAMP-turbidimetric assay to detect α0-thalassemia (SEA deletion). The developed LAMP turbidimetric assay demonstrated a sensitivity and specificity of 100% (36/36 × 100) and 97.7% (170/174 × 100), respectively, when compared with gap-PCR. Furthermore, we propose a strategy involving the addition of the low-cost LAMP-turbidimetric assay before performing the gold standard. This strategy represents a cost-saving of USD 2,608 based on 210 samples that required DNA analysis. Finally, the developed LAMP turbidimetric assays offer advantages such as reduced time, workload, cost savings, no need for highly developed instruments, and a straightforward interpreting process. Therefore, implementation of LAMP assays into routine settings would be improve the efficiency of prevention and control program for severe thalassemia disease in this region.


Subject(s)
Hydrops Fetalis , alpha-Thalassemia , Female , Pregnancy , Humans , Retrospective Studies , Thailand/epidemiology , Hydrops Fetalis/diagnosis , alpha-Thalassemia/diagnosis , Cost Savings
12.
Int J Hematol ; 119(4): 374-382, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38411864

ABSTRACT

Thalassemia is a highly prevalent hematologic disease in Guizhou, China. This study aimed to determine the epidemiological characteristics of thalassemia in couples at childbearing age and assess the neonatal risk of thalassemia in this subpopulation. A cohort of 4481 couples at childbearing age were recruited for thalassemia carrier screening by both traditional hematological tests and next-generation sequencing. Of them, 1314 (14.66%) thalassemia carriers were identified, including 857 (9.76%) α-thalassemia, 391 (4.36%) ß-thalassemia, and 48 (0.54%) composite α and ß-thalassemia. A total of 12 α-globin gene alterations and 16 ß-globin mutations were detected, including four novel thalassemia mutations. SEA was the most common α-thalassemia genotype (26.86%), CD41-42 the most common ß-thalassemia genotype (36.57%), and αα/- α3.7 + CD41-42 the most common composite α- and ß-thalassemia genotype (18.75%). Ethnically, the Zhuang had the highest rate of thalassemia gene carriers among the ethnic groups. Geographically, Qiannan had the highest rate of thalassemia gene carriers. In addition, 38 of the 48 couples with composite α- and ß-thalassemia were high-risk thalassemia carriers, and 4 carrying the -SEA/αα gene needed fertility guidance.


Subject(s)
alpha-Thalassemia , beta-Thalassemia , Infant, Newborn , Humans , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics , beta-Thalassemia/diagnosis , alpha-Thalassemia/epidemiology , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Prevalence , Genotype , Mutation , China/epidemiology , Fertility , Risk Assessment
13.
Hemoglobin ; 48(2): 94-100, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38390736

ABSTRACT

To assess the roles of genetic modifiers in Iraqi ß-thalassemia patients, and determine whether a genotype-based scoring system could be used to predict phenotype, a total of 224 Iraqi patients with molecularly characterized homozygous or compound heterozygous ß-thalassemia were further investigated for α-thalassemia deletions as well as five polymorphisms namely: rs7482144 C > T at HBG2, rs1427407 G > T and rs10189857 A > G at BCL11A, and rs28384513 A > C and rs9399137 T > C at HMIP. The enrolled patients had a median age of 14 years, with 96 males and 128 females. They included 144 thalassemia major, and 80 thalassemia intermedia patients. Multivariate logistic regression analysis revealed that a model including sex and four of these genetic modifiers, namely: ß+ alleles, HBG2 rs7482144, α-thalassemia deletions, and BCL11A rs1427407 could significantly predict phenotype (major versus intermedia) with an overall accuracy of 83.9%. Furthermore, a log odds genetic score based on these significant predictors had a highly significant area under curve of 0.917 (95% CI 0.882-0.953). This study underscores the notion that genetic scoring systems should be tailored to populations in question, since genetic modifiers (and/or their relative weight) vary between populations. The population-oriented genetic scoring system created by the current study to predict ß-thalassemia phenotype among Iraqis may pave the way to personalized medicine in this patient's group.


Subject(s)
Phenotype , Polymorphism, Single Nucleotide , Precision Medicine , Repressor Proteins , beta-Thalassemia , Humans , beta-Thalassemia/genetics , beta-Thalassemia/diagnosis , Male , Female , Iraq , Adolescent , Child , Genotype , Alleles , Adult , Young Adult , Child, Preschool , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis
14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(1): 214-218, 2024 Feb.
Article in Chinese | MEDLINE | ID: mdl-38387924

ABSTRACT

OBJECTIVE: To analyze the genotype distribution and hematological characteristics of children with thalassemia in Chongqing. METHODS: A total of 207 children with thalassemia admitted to Chongqing University Three Gorges Hospital from January 2021 to October 2022 were selected as the research objects. The genotype distribution and hematological characteristics were retrospectively analyzed. RESULTS: 207 cases of thalassemia were confirmed from 482 samples by gene detection, the detection rate was 42.95%, α-thalassemia accounted for 17.63%(85/482), ß-thalassemia accounted for 24.27%(117/482), and compound αß thalassemia accounted for 1.04%(5/482). A total of 5 gene mutation types of α-thalassaemia were detected in this study, which constituted 6 genotypes, αα/-SEA was the most common one, followed by αα/-α3.7. A total of 8 gene mutation types of ß-thalassemia were detected, which constituted 9 genotypes, the top three were CD17/N, CD654/N and CD41-42/N. The highest detection rate was found in the patients aged 0-3 years (57%), and the degree of anemia was mainly mild (88.41%). 97.58% of the patients were MCV< 80 fl, 98.55% were MCH< 28 pg, 60.87% were MCHC< 320 g/L, and 71.50% were RDW-SD < 37%. The MCV and MCH of ß-thalassemia group were lower than that of α-thalassemia group, and the MCHC was higher than that of α-thalassemia group (P <0.05), but RDW-SD was not significantly different between the two groups (P >0.05). There were no significant differences in MCV, MCH, MCHC and RDW-SD between ß+/ßN and ß0/ßN groups ( P >0.05). The MCV and RDW-SD of --/αα thalassemia group were lower than that in -α/αα thalassemia group, the differences were statistically significant (P < 0.05), but MCH and MCHC were not significantly different between the two groups (P >0.05). CONCLUSION: The genotypes of children with thalassemia in Chongqing are diverse and heterogeneous, and the majority of them are mild anemia. There are differences in haematological indexes among different genotypes of thalassemia.


Subject(s)
alpha-Thalassemia , beta-Thalassemia , Child , Humans , beta-Thalassemia/genetics , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Retrospective Studies , Genotype , Mutation , China/epidemiology
15.
Blood Rev ; 64: 101165, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38182489

ABSTRACT

α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and ß globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency.


Subject(s)
Hematologic Diseases , Iron Overload , alpha-Thalassemia , beta-Thalassemia , Humans , beta-Thalassemia/therapy , alpha-Thalassemia/diagnosis , alpha-Thalassemia/genetics , alpha-Thalassemia/therapy , Erythropoiesis , Erythrocyte Transfusion , Iron Overload/diagnosis , Iron Overload/etiology , Iron Overload/therapy
16.
J Med Screen ; 31(1): 53-57, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37439030

ABSTRACT

OBJECTIVES: As one of the most common hereditary diseases, thalassemia affects a large number of people in China. The aim of this study was to investigate the feasibility of a method based on next-generation sequencing (NGS) for screening of thalassemia carriers among high school students in the Shaoguan area. MATERIALS AND METHODS: The NGS-based method was performed using 25,910 high school students recruited from 38 schools. The screening yield was systematically analyzed. Before screening, a lecture on how the disease is inherited, the symptoms of thalassemia, and how to prevent it was given to 28,780 students. RESULTS: Implying successful delivery of information on the disease, 90.03% (25,910 of 28,780) of the students agreed to join this program for thalassemia screening. A thalassemia carrier rate of 15.99% (4144 of 25,910) was found. Also, 69 rare genotypes (28 of α-thalassemia and 41 of ß-thalassemia) and 9 novel variants were identified. CONCLUSIONS: This NGS-based method provided a feasible platform for high school population thalassemia screening. Combined with a clinical follow-up strategy, it could help eventually to prevent the births of affected children.


Subject(s)
alpha-Thalassemia , beta-Thalassemia , Child , Humans , Early Detection of Cancer , beta-Thalassemia/diagnosis , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics , China/epidemiology , Genotype , alpha-Thalassemia/diagnosis , alpha-Thalassemia/epidemiology , alpha-Thalassemia/genetics , Students , Mutation
17.
J Hum Genet ; 69(2): 101-105, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37904029

ABSTRACT

Partial duplications of genes can be challenging to detect and interpret and, therefore, likely represent an underreported cause of human disease. X-linked dominant variants in ATRX are associated with Alpha-thalassemia/impaired intellectual development syndrome, X-linked (ATR-X syndrome), a clinically heterogeneous disease generally presenting with intellectual disability, hypotonia, characteristic facies, genital anomalies, and alpha-thalassemia. We describe an affected male with a de novo hemizygous intragenic duplication of ~43.6 kb in ATRX, detected by research genome sequencing following non-diagnostic clinical testing. RNA sequencing and DNA methylation episignature analyses were central in variant interpretation, and this duplication was subsequently interpreted as disease-causing. This represents the smallest reported tandem duplication within ATRX associated with disease. This case demonstrates the diagnostic utility of integrating multiple omics technologies, which can ultimately lead to a definitive diagnosis for rare disease patients.


Subject(s)
Intellectual Disability , Mental Retardation, X-Linked , alpha-Thalassemia , Humans , Male , alpha-Thalassemia/diagnosis , alpha-Thalassemia/genetics , X-linked Nuclear Protein/genetics , DNA Copy Number Variations/genetics , Mental Retardation, X-Linked/diagnosis , Mental Retardation, X-Linked/genetics , Intellectual Disability/diagnosis , Intellectual Disability/genetics
19.
Mol Genet Genomic Med ; 12(1): e2344, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38112059

ABSTRACT

BACKGROUND: Thalassemia is a common genetic disorder in southwestern China, and an increasing number of cases from eastern China have been recently reported. Here, we developed a rapid, convenient, and accurate assay to evaluate the mutation spectrum of thalassemia in eastern China. METHODS: A carrier screening assay for 61 hotspot variants among HBA1/HBA2 and HBB (OMIM: 141800, 141850, and 141900) genes was developed by SNaPshot/high-throughput ligation-dependent probe amplification (HLPA) technology. We used this assay to detect the mutation spectrum of thalassemia in individuals from eastern China and compared with the data collected from literatures focused on southern and northern China for variant distribution. RESULTS: Among 4276 tested individuals, 2.62% (112/4276) were α-thalassemia carriers, with 90 carrying one deletion or mutation and 22 carrying two deletions. 0.40% (17/4276) were ß-thalassemia carriers, and the most common variant of ß-thalassemia was c.126_129delCTTT (29.41%) followed by c.316-197C>T (23.53%). The genotype distribution in our study was similar to those from southern China populations. CONCLUSION: The Chinese population from different regions presented comparable mutation spectrum of thalassemia, and the SNaPshot/HLPA technique may serve as a capable assay for a routine genetic test in clinical practice with its accurate, rapid, and inexpensive advantage.


Subject(s)
alpha-Thalassemia , beta-Thalassemia , Adult , Pregnancy , Female , Humans , beta-Thalassemia/genetics , beta-Thalassemia/diagnosis , Multiplex Polymerase Chain Reaction , alpha-Thalassemia/diagnosis , Mutation , Genotype
20.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(6): 1811-1814, 2023 Dec.
Article in Chinese | MEDLINE | ID: mdl-38071065

ABSTRACT

OBJECTIVE: To investigate characteristics of silent alpha thalassemia genes in child-bearing adults in Guangdong, in order to provide data for the prevention and control of hemoglobin H disease. METHODS: A total of 8 752 cases were collected from January 2016 to December 2020. Gap-PCR was used to detect the deletional of α-thalassemia mutations (-α3.7, -α4.2), while PCR reverse dot blot hybridization assay (RDB) was used to detect the non-deletional α-thalassemia mutations (Hb CS, Hb QS and Hb Westmead). RESULTS: Among 8 752 subjects, 717 cases of silent α-thalassemia were detected, the detection rate was 8.19%, including 555 cases of deletional α-thalassemia (77.41%) and 162 cases of non-deletional α-thalassemia 22.59%. The mean corpuscular volume (MCV) of deletional silent α-thalassemia was (82.09±4.10) fl, and mean corpuscular hemoglobin (MCH) was (27.03±1.37) pg, which both were over the diagnostic cut-off value for thalassemia. The MCV of non-deletional silent α-thalassemia was (81.07±4.93) fl, and MCH was (26.77±2.20) pg. According to the diagnostic criteria, if using MCV<82 fl or (and) MCH<27 pg as a positive criteria for screening thalassemia in the childbearing age, the screening sensitivity was 53.14% and different in different genotype, among which ααQS/αα was 100%, -α3.7/αα, -α4.2/αα, ααCS/αα and ααWS/αα was 62.15%, 63.41%, 44.83% and 39.62%, respectively. Namely, nearly half the carriers of such mutations might have escaped detection as a result of their screening strategy. CONCLUSION: When a couple is preparing for pregnancy, if one of them has been determined to be mild α-thalassemia or hemoglobin H disease, other half is necessary to carry out silent α thalassemia detection to prevent the birth of children with hemoglobin H disease even if MCV>82 fl and MCH>27 pg.


Subject(s)
alpha-Thalassemia , beta-Thalassemia , Adult , Pregnancy , Female , Humans , alpha-Thalassemia/genetics , alpha-Thalassemia/diagnosis , Genotype , Mutation , Erythrocyte Indices , Polymerase Chain Reaction , China , beta-Thalassemia/genetics
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