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1.
Hemoglobin ; 48(1): 60-62, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38314576

ABSTRACT

Patients with the genotype of ß0/ß0 for ß-thalassemia (ß-thal) usually behave as ß-thal major (ß-TM) phenotype which is transfusion-dependent. The pathophysiology of ß-thal is the imbalance between α/ß-globin chains. The degree of α/ß-globin imbalance can be reduced by the more effective synthesis of γ-globin chains, and increased Hb F levels, modifying clinical severity of ß-TM. We report a Chinese child who had homozygous ß0-thal and a heterozygous KLF1 mutation. The patient had a moderate anemia since 6 months old, keeping a baseline Hb value of 8.0-9.0 g/dL. She had normal development except for a short stature (3rd percentile) until 6 years old, when splenomegaly and facial bone deformities occurred. Although genetic alteration of KLF1 expression in ß0/ß0 patients can result in some degree of disease alleviation, our case shows that it is insufficient to ameliorate satisfactorily the presentation. This point should be borne in mind for physicians who provide the genetic counseling and prenatal diagnosis to at-risk families.


Subject(s)
beta-Globins , beta-Thalassemia , Child , Female , Humans , Infant , alpha-Globins/genetics , beta-Globins/genetics , beta-Thalassemia/genetics , China , Follow-Up Studies , Genotype , Mutation
2.
Eur J Pediatr ; 183(3): 1367-1379, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38165465

ABSTRACT

Circular RNA circ-0008102 has previously been found dysregulated in ß-thalassemia (ß-thal) in circRNAs microarray (GSE196682 and GSE241141). Our study is aimed at identifying whether circ-0008102 could be a novel biomarker in ß-thal. The peripheral blood of pediatric ß-thal patients with (n = 39) or without (n = 20) blood transfusion and healthy controls (n = 30) was selected. qRT-PCR, ROC curve analysis, Spearman correlation analysis, and FISH were used to analyze clinical value of circ-0008102. qRT-PCR confirmed that circ-0008102 expression in pediatric ß-thal patients without blood transfusion was significantly higher. ROC curves analysis showed that the AUC of circ-0008102 for differentiating patients without blood transfusion from patients with blood transfusion and healthy controls with an AUC of 0.733 and 0.711. Furthermore, circ-0008102 expression was positively correlated with the levels of RBC, HbF, ß-globin, and γ-globin mRNA, but was negatively corrected with the levels of HbA and Cr. circ-0008102 was mainly located in the cytoplasm. circ-0008102 could induce the activation of γ-globin and negatively regulate the expression of the five highest-ranking candidate miRNAs (miR-372-3p, miR-329-5p, miR-198, miR-152-5p, and miR-627-3p) in K562 cells. CONCLUSION: We demonstrate that peripheral blood upregulated circ-0008102 may serve as a novel clinical biomarker for pediatric ß-thal without blood transfusion. WHAT IS KNOWN: • CircRNAs are known to be involved in various human diseases, and several circRNAs are regarded as a class of promising blood-based biomarkers for detection of ß-thal. • CircRNAs exert biological functions by epigenetic modification and gene expression regulation, and dysregulated circRNAs in ß-thal might be involved in the induction of HbF in ß-thal. WHAT IS NEW: • Peripheral blood circ-0008102 maybe serve as a novel clinical biomarker for detection of pediatric ß-thal without blood transfusion. • Circ-0008102 participates in the pathogenesis of ß-thal through regulating γ-globin expression, and negatively regulates the expression of miR-372-3p, miR-329-5p, miR-198, miR-152-5p and miR-627-3p.


Subject(s)
MicroRNAs , beta-Thalassemia , Humans , Child , RNA, Circular/genetics , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics , gamma-Globins , MicroRNAs/genetics , MicroRNAs/metabolism , Biomarkers
3.
Chembiochem ; 25(1): e202300700, 2024 01 02.
Article in English | MEDLINE | ID: mdl-37917145

ABSTRACT

Flavin-dependent halogenases allow halogenation of electron-rich aromatic compounds under mild reaction conditions even at electronically unfavored positions with high regioselectivity. In order to expand the application of halogenases, the enzymes need to be improved in terms of stability and efficiency. A previous study with the tryptophan 6-halogenase Thal demonstrated that thermostable Thal variants tend to form dimers in solution while the wild type is present as a monomer. Based on this a dimeric Thal variant was generated that is covalently linked by disulfide bonds. Introducing two cysteine residues at the dimer interface resulted in the variant Thal CC with significantly increased thermostability (▵T50 =15.7 K) and stability over time at elevated temperature compared to the wild type. By introducing the homologous mutations into the tryptophan 5-halogenase PyrH, we were able to show that the stabilization by covalent dimerization can also be transferred to other halogenases. Moreover, it was possible to further increase the thermostability of PyrH by inserting cysteine mutations at alternative sites of the dimer interface.


Subject(s)
Cysteine , Tryptophan , Tryptophan/metabolism , Halogenation , Flavins/metabolism
4.
Hemoglobin ; 47(2): 102-104, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37247248

ABSTRACT

We report three cases of fetalis hydrops associated with nondeletional α-thalassemia. Two cases were caused by hemoglobin (Hb) H-Quong Sz disease, and one caused by homozygous Hb Constant Spring. Fetal hydrops occurred in the late second trimester in all three cases. Our study indicates that for pregnancies at risk for fetal nondeletional Hb H disease, strict ultrasound follow-up is particularly important. Even without techniques of intrauterine transfusion treatment, early prenatal diagnosis can enable parents to make timely decisions.


Subject(s)
Hemoglobins, Abnormal , alpha-Thalassemia , Pregnancy , Female , Humans , Hydrops Fetalis/diagnosis , Hydrops Fetalis/etiology , Hemoglobin H , Fetal Hemoglobin , alpha-Thalassemia/complications , alpha-Thalassemia/diagnosis , alpha-Thalassemia/genetics , Hemoglobins, Abnormal/genetics , Prenatal Diagnosis
5.
Hemoglobin ; 47(1): 3-10, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36890736

ABSTRACT

Hemoglobinopathies, including α- and ß-thalassemias and sickle cell disease, are among the most widely disseminated hereditary blood disorders worldwide. Bangladesh is considered a hotspot for hemoglobinopathies, and these diseases cause a significant health concern in the country. However, the country has a dearth of knowledge on the molecular etiology and carrier frequency of thalassemias, primarily due to a lack of diagnostic facilities, limited access to information, and the absence of efficient screening programs. This study sought to investigate the spectrum of mutations underlying hemoglobinopathies in Bangladesh. We developed a set of polymerase chain reaction (PCR)-based techniques to detect mutations in α- and ß-globin genes. We recruited 63 index subjects with previously diagnosed thalassemia. Along with age- and sex-matched control subjects, we assessed several hematological and serum indices and genotyped them using our PCR-based methods. We identified that parental consanguinity was associated with the occurrence of these hemoglobinopathies. Our PCR-based genotyping assays identified 23 HBB genotypes, with the codons 41/42 (-TTCT) (HBB: c.126_129delCTTT) mutation leading the spectrum. We also observed the presence of cooccurring HBA conditions, of which the participants were not aware. All index participants in this study were on iron chelation therapies, yet we found they had very high serum ferritin (SF) levels, indicating inefficient management of the individuals undergoing such treatments. Overall, this study provides essential information on the hemoglobinopathy mutation spectrum in Bangladesh and highlights the need for nationwide screening programs and an integrated policy for diagnosing and managing individuals with hemoglobinopathies.


Subject(s)
Hemoglobinopathies , Thalassemia , Humans , Bangladesh/epidemiology , Hemoglobinopathies/diagnosis , Hemoglobinopathies/epidemiology , Hemoglobinopathies/genetics , Mutation , beta-Globins/genetics
6.
J Alzheimers Dis ; 91(2): 683-695, 2023.
Article in English | MEDLINE | ID: mdl-36502330

ABSTRACT

BACKGROUND: The strongest risk factor for the development of Alzheimer's disease (AD) is age. The progression of Braak stage and Thal phase with age has been demonstrated. However, prior studies did not include cognitive status. OBJECTIVE: We set out to define normative values for Alzheimer-type pathologic changes in individuals without cognitive decline, and then define levels that would qualify them to be resistant to or resilient against these changes. METHODS: Utilizing neuropathology data obtained from the National Alzheimer's Coordinating Center (NACC), we demonstrate the age-related progression of Alzheimer-type pathologic changes in cognitively normal individuals (CDR = 0, n = 542). With plots generated from these data, we establish standard lines that may be utilized to measure the extent to which an individual's Alzheimer-type pathology varies from the estimated normal range of pathology. RESULTS: Although Braak stage and Thal phase progressively increase with age in cognitively normal individuals, the Consortium to Establish a Registry for Alzheimer's Disease neuritic plaque score and Alzheimer's disease neuropathologic change remain at low levels. CONCLUSION: These findings suggest that an increasing burden of neuritic plaques is a strong predictor of cognitive decline, whereas, neurofibrillary degeneration and amyloid-ß (diffuse) plaque deposition, both to some degree, are normal pathologic changes of aging that occur in almost all individuals regardless of cognitive status. Furthermore, we have defined the amount of neuropathologic change in cognitively normal individuals that would qualify them to be "resilient" against the pathology (significantly above the normative values for age, but still cognitively normal) or "resistant" to the development of pathology (significantly below the normative values for age).


Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/pathology , Neurofibrillary Tangles/pathology , Amyloid beta-Peptides , Aging/pathology , Plaque, Amyloid/pathology
7.
Front Pediatr ; 10: 974496, 2022.
Article in English | MEDLINE | ID: mdl-36533237

ABSTRACT

Abstract: We report the haematological parameters and molecular characterization of beta zero (ß°) South East Asia (SEA) deletion in the HBB gene cluster with unusually high levels of Hb F compared to a classical heterozygous beta zero (ß°)-thalassaemia. Methods: Retrospective study on 17 cases of (ß°) South East Asia (SEA) deletion from 2016 to 2019 referred to Institute for Medical Research were conducted. The clinical information and haematological profiles were evaluated. The mutation was analyzed, and the results were compared with other ß°-thalassaemia groups. For HBB gene genotyping, all the cases were subjected for multiplex gap-PCR, 5 cases were subjected for HBB gene sequencing for exclusion of compound heterozygous with other beta variants. Co-inheritance of α-thalassaemia were determined using multiplex gap-PCR and multiplex ARMS-PCR. Results: Seventeen cases were positive for ß°-thal SEA deletion. Fifteen cases were heterozygous and two were compound heterozygous for ß°-thal SEA deletion. The results were compared with 182 cases of various heterozygous ß° deletions and mutations. The mean Hb for heterozygous ß°-thal SEA deletion (13.44 ± 1.45 g/dl) was normal and significantly higher than heterozygous IVS 1-1 and Codon 41/42 (post hoc test, p < 0.05). The medians for the MCV and MCH of ß°-thal SEA deletion were significantly higher than for all heterozygote ß°-thalassaemia traits (Mann Whitney test, p < 0.05). Patients with ß°-thal SEA deletion had elevated levels of Hb A2 consistent with ß-thalassaemia traits, with Hb F levels consistent with HPFH or δß-thalassaemia carriers. The median for Hb A2 was 4.00 + 1.00%, similar to that observed in other ß°-thalassaemia groups except for IVS 1-1 mutation (median 5.30 + 0.45%) and ß°-Filipino (∼45 kb deletion) deletion (median 6.00 + 0.58). Interestingly, we found that Hb F levels for ß°-thal SEA deletion were statistically higher than other ß°-thalassaemia mutations (median 19.00 + 5.50%, p < 0.05), except for the ß°-thal 3.5 kb deletion group. Conclusion: We conclude that ß°-thal SEA deletion has a unique haematological parameters of beta zero thalassaemia trait. We affirm to classifying this deletion as SEA-HPFH based on previous studies considering the phenotype features rather than the molecular defect of ß°-thal SEA deletion, as this will make it easier to offer genetic counselling to affected individuals.

8.
Hemoglobin ; 46(5): 290-295, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36412578

ABSTRACT

ß-Thalassemia (ß-thal) is one of the most common monogenic recessive inherited diseases worldwide. The mutation spectrum of ß-thal has been increasingly broadened by various genetic testing methods. The discovery and identification of novel and rare pathogenic thalassemia variants enable better disease prevention, especially in high prevalence regions. In this study, a Chinese thalassemia family with an unclear etiology was recruited to the Thalassemia Screening Program. Blood samples collected from them were primarily screened by hematology analysis and clinical routine genetic screening. Subsequently, targeted next-generation sequencing (NGS) and Sanger sequencing were performed to find and identify a novel deletion variant. The deletion, discovered by targeted NGS, was validated through real-time quantitative polymerase chain reaction (qPCR). First, a large novel ß-thal deletion (3488 bp) related to a high Hb F level, NC_000011.9: g.5245533_5249020del (Chongqing deletion) (GRCh37/hg19), was found and identified in the proband and her mother. The deletion removed the entire ß-globin gene and led to absent ß-globin (ß0). We then validated this large novel deletion in the proband and her mother by qPCR. We first discovered and identified a large novel ß-thal deletion related to elevated Hb F level, it helps broaden the spectrum of pathogenic mutants that may cause ß-thal intermedia (ß-TI) or ß-thal major (ß-TM), paving the way for effective thalassemia screening. Next-generation sequencing has the potential of finding rare and novel thalassemia mutants.


Subject(s)
beta-Thalassemia , Female , Humans , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics , Mutation , beta-Globins/genetics , Alleles , High-Throughput Nucleotide Sequencing
9.
Hemoglobin ; 46(5): 285-289, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36367309

ABSTRACT

Hemoglobinopathies are common genetic disorders of the hemoglobin (Hb) molecule. Globally, 7.0% of the population are carriers of thalassemia with 300,000-400,000 affected births each year. There are >40 million carriers of ß-thalassemia (ß-thal) in India with 10,000-12,000 affected births every year. This makes control programs crucial in this vast and diverse country. The present study was undertaken to find out the burden of hemoglobinopathies, and in particular, the prevalence of ß-thal carriers in the population of Saurashtra region of Gujarat in Western India. A total of 16,780 individuals, including school and college students, were screened. Complete blood counts (CBCs) and high performance liquid chromatography (HPLC) analysis were performed. We detected 1891 (11.26%) individuals with different hemoglobinopathies, of whom 758 (4.52%) were diagnosed to carry ß-thal trait, 104 (0.62%) carried Hb D-Punjab (HBB: c.364G>C) trait, 61 (0.36%) carried sickle cell trait, 32 (0.19%) carried δß-thal trait/HPFH (hereditary persistence of fetal Hb) trait, and other hemoglobinopathies were identified in smaller numbers (0.15%). We encountered 27 individuals with mean corpuscular Hb (MCH) <27.0 pg and mean corpuscular volume (MCV) <80.0 fL levels, who had borderline Hb A2 levels (3.2-3.5%). Twenty castes showed the presence of ß-thal or other hemoglobinopathies. A high prevalence of ß-thal was found in the Sindhis (11.67%), Lohanas (9.71%), Brahmins (6.31%), Bharvads (6.94%), Harijans (7.57%) and Vankars (7.77%). All the heterozygotes were given appropriate counseling. A multi pronged approach, including screening of high school and college students, needs to be considered for this vast and ethnically diverse country to reduce the burden of hemoglobinopathies.


Subject(s)
Hemoglobinopathies , Thalassemia , beta-Thalassemia , Humans , beta-Thalassemia/diagnosis , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics , Hemoglobinopathies/diagnosis , Hemoglobinopathies/epidemiology , Hemoglobinopathies/genetics , Heterozygote , Fetal Hemoglobin/genetics , India/epidemiology
10.
J Laparoendosc Adv Surg Tech A ; 32(11): 1183-1189, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36126310

ABSTRACT

Introduction: The aim of this study was to compare the long-term outcomes of laparoscopic complete (Nissen) fundoplication (LNF) with laparoscopic partial (Thal) fundoplication (LTF) in children. This is the only prospective, randomized study to follow patients up for more than 10 years. Interim results published in 2011 at median 2.5 year follow-up showed that LNF had a significantly lower failure rate compared with LTF. Materials and Methods: A randomized, controlled trial of LNF versus LTF in children (<16 years) was performed. The primary outcome measure was "absolute" failure of the fundoplication-recurrence of symptoms that merited either reoperation or insertion of transgastric jejunostomy (GJ). Secondary outcomes were "relative" failure (need for postop antireflux medication), complications (e.g., dysphagia), and death. Results: One hundred seventy-five patients were recruited; 89 underwent LNF, and 86 underwent LTF. Eight patients had no follow-up recorded. At long-term follow-up, 59 patients had died (35%); LNF 37/85 (43.5%) and LTF 22/82 (26.8%), P = .02. Median length of follow-up in survivors was 132 months. There was no statistically significant difference in "absolute" failure rate between LNF 8/85(9.4%) and LTF 15/82 (18%), P = .14. There was no difference in "relative" failure between LNF 7/85 (8.2%) and LTF 12/82 (14%), P = .23. Long-term dysphagia affected 5 out of 108 (4.6%) patients; 3/48 (6.2%) of LNF and 2/60 (3.3%) of LTF (P = .65). Conclusions: There was no statistically significant difference in 'absolute' failure between LNF and LTF at long-term follow-up. Neurologically impaired children have a high mortality rate following fundoplication due to comorbidities. This trial commenced in 1998 and was approved by the Oxfordshire Research Ethics Committee (No. 04.OXA.18-1998).


Subject(s)
Deglutition Disorders , Gastroesophageal Reflux , Laparoscopy , Child , Humans , Fundoplication/methods , Deglutition Disorders/etiology , Gastroesophageal Reflux/surgery , Gastroesophageal Reflux/complications , Prospective Studies , Treatment Outcome , Laparoscopy/methods , Follow-Up Studies
11.
Hemoglobin ; 46(2): 137-139, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35980111

ABSTRACT

The 3' untranslated region (3'UTR) is associated with mRNA stability because of its involvement in 3' end processing, polyadenylation, and mRNA capping. Mutations located in this area can cause a phenotype compatible with ß+-thalassemia (ß+-thal). We report a Chinese subject with ß-thal intermedia (ß-TI) who developed transfusion-dependent anemia. Molecular studies revealed that the patient was a compound heterozygote for two ß-thal alleles: codons 41/42 (-TTCT) (HBB: c.126_129delCTTT) and term codon +32 (A>C) (HBB: c.*32A>C).


Subject(s)
beta-Thalassemia , 3' Untranslated Regions , Codon , Humans , Mutation , Phenotype , beta-Globins/genetics , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics , beta-Thalassemia/therapy
12.
Hemoglobin ; 46(2): 118-123, 2022 Mar.
Article in English | MEDLINE | ID: mdl-36000542

ABSTRACT

Thalassemia is the most common inherited hemoglobinopathy worldwide. Variation of clinical symptoms in this hemoglobinopathy entails differences in disease-onset and transfusion requirements. The aim of this study was to investigate the role of α-globin gene deletions in modulating the clinical heterogeneity of ß-thalassemia (ß-thal) syndromes. A total number 270 ß-thal subjects were enrolled. Hematological parameters were recorded. ß-Globin mutations were determined by amplified refractory mutation system-polymerase chain reaction (ARMS-PCR), gap-PCR and Sanger sequencing. α-Globin gene deletions were determined by multiplex PCR. Out of 270 ß-thal subjects, 19 carried ß+/ß+, 74 had ß0/ß0 and 177 had the ß0/ß+ genotype. When we determined the severity of the different ß-thal subjects in coinherited with the α gene deletion, it was revealed that, 84.2% ß+/ß+ subjects carried a non severe phenotype and did not have an α gene deletion. Of the ß0/ß0 individuals, 95.9% presented a severe phenotype, irrespective of α-globin gene deletions. In cases with the ß0/ß+ genotype, 19.2% subjects also carried a deletion on the α gene. Of these, 61.8% presented a non severe phenotype and 38.2% were severely affected. Only in the ß0/ß+ category did α gene deletions make a significant contribution (p < 0.001) toward alleviation of clinical severity. Therefore, it can be stated that α-globin gene deletions play a role in ameliorating the phenotype in patients with a ß+/ß0 genotype.


Subject(s)
Hemoglobinopathies , alpha-Thalassemia , beta-Thalassemia , Genotype , Hemoglobinopathies/genetics , Humans , Mutation , Phenotype , alpha-Globins/genetics , alpha-Thalassemia/diagnosis , alpha-Thalassemia/genetics , beta-Globins/genetics , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics
13.
Hemoglobin ; 46(1): 12-14, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35950582

ABSTRACT

The estimated population of Pakistan is approximately 225,633,392 (225 million). The healthcare delivery system of Pakistan is complex because it includes healthcare subsystems operated by both the federal government and the provincial government. In Pakistan ß-thalassemia (ß-thal) trait frequency ranges between 5.0-7.0%, thus, there are more than 10 million carriers in the country; and every year, around 5000 children are diagnosed to carry ß-thal major (ß-TM) in Pakistan. No standard management protocols exist and blood transfusion remains the mainstay of management. Most of the population belong to the lower socioeconomic strata, family units are large and therefore cannot afford to pay for treatment and management of their thalassemic child. Currently in Pakistan, at the national level, not a single thalassemia prevention program is available to counter this disease. However, at the provincial level some initiatives have been taken, legislation has been approved for premarital screening in Sindh, Khyber Pakhtunkhwa (KPK) and Baluchistan, but implementation remains the issue.


Subject(s)
Thalassemia , beta-Thalassemia , Child , Heterozygote , Humans , Mass Screening , Pakistan/epidemiology , Thalassemia/diagnosis , Thalassemia/epidemiology , Thalassemia/therapy , beta-Thalassemia/diagnosis , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics
14.
Hemoglobin ; 46(1): 66-70, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35950588

ABSTRACT

ß-Thalassemia (ß-thal) is highly prevalent in Myanmar, but limited data are available on the molecular basis and the clinical manifestations in Myanmar patients. In this study, we investigated the clinical features and ß-globin gene abnormalities in 15 homozygous ß-thal and 60 Hb E (HBB: c.79G>A)/ß-thal pediatric patients who attended Yangon Children Hospital, the biggest thalassemia day care unit center in Myanmar. Eight different ß0-thal mutations were identified, with four accounting for 88.9% of alleles studied (excluding the Hb E variant). A genotype-phenotype correlation was found; all homozygous ß0-thalassemias had severe clinical courses, whereas the highly variable disease severity was demonstrated among Hb E/ß0-thal patients. Interactions of IVS-I-1 (G>T) (HBB: c0.92+1G>T) ß0-thal with Hb E are associated with milder clinical symptoms. The number of mildly affected Hb E/ß-thal patients was lower than expected, suggesting that there may be a considerable number of patients in the population who have either not been admitted to hospital or diagnosed with carrying the disease. Although the clinical severity in the Myanmar ß-thal patients seems to be similar to that in other populations, the levels of hemoglobin (Hb) appears to be very low. These findings indicate the need for the improvement of patient management and the development of prevention and control programs for ß-thal in Myanmar.


Subject(s)
alpha-Thalassemia , beta-Thalassemia , Genetic Association Studies , Humans , Mutation , Myanmar/epidemiology , alpha-Thalassemia/genetics , beta-Globins/genetics , beta-Thalassemia/diagnosis , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics
15.
Hemoglobin ; 46(2): 87-90, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35930292

ABSTRACT

Hemoglobinopathies are the most common single-gene disorders, and ß-thalassemia (ß-thal) imposes a tremendous health burden on Turkey. Thus, premarital carrier screening is obligatory in Turkey, as it is in some other countries. As a result of this mandatory procedure, at routine clinical checkups, many individuals who had undergone premarital screening but did not have any clinical symptoms and/or hematological findings, have compulsorily been required to undergo further evaluation due to abnormal levels of hemoglobin (Hb) fractions (Hb A, Hb A2 and Hb F). Many consequences, such as mutations in unrelated gene(s) or someone's nutritional status, have been reported to affect the Hb fractions levels. In the present study, we aimed to determine whether HBD has a molecular causative role in patients with low Hb A2 levels (below 1.8%). The study was conducted with 20 individuals with low Hb A2 levels who had applied to our outpatient clinic. All DNA samples were analyzed for the HBD gene. Nineteen of the 20 subjects were diagnosed to carry a mutation with one of four different δ-globin variants. Three of them had been described previously [Hb A2-Yialousa (HBD: c.82G>T), Hb A2-Bornova (HBD: c.350G>C) and Hb A2-Yokoshima (HBD: c.77G>A)]. The novel [δ10(A7)Ala→Val, HBD: c.32C>T] mutation was defined as a new δ variant and reported to the HbVar database as Hb A2-Canakkale. In conclusion, the molecular characterization of Hb A2 low levels has been suggested to be significant for a definite diagnosis and counseling.


Subject(s)
beta-Thalassemia , delta-Globins , Cohort Studies , Hemoglobin A2/analysis , Hemoglobin A2/genetics , Humans , Mutation , Turkey , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics , delta-Globins/genetics
16.
Hemoglobin ; 46(4): 253-255, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35686459

ABSTRACT

We report a de novo frameshift mutation in exon 3 of the ß-globin gene that leads to a ß-thalassemia (ß-thal) intermedia (ß-TI) phenotype in a 6-year-old Chinese boy. This novel mutation with deletion of the last nucleotide (-T) at codon 130 results in a ß-globin chain that is extended to 156 amino acid residues. This study highlights the importance of considering dominantly inherited ß-thal in the investigation of anemia, even in patients with ethnic backgrounds not usually associated with ß-thal and hematologically normal parents.


Subject(s)
beta-Globins , beta-Thalassemia , Humans , beta-Globins/genetics , beta-Globins/chemistry , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics , Nucleotides , Exons , Codon , Mutation
17.
Hemoglobin ; 46(3): 184-186, 2022 May.
Article in English | MEDLINE | ID: mdl-35543019

ABSTRACT

Hb Dhonburi (also known as Hb Neapolis) (HBB: c.380T>G) is an unstable hemoglobin (Hb) variant that cannot be detected by high performance liquid chromatography (HPLC) or capillary electrophoresis (CE) in routine laboratory diagnosis. This could lead to prenatal misdiagnosis unless a molecular analysis is applied. Here, we report a Thai couple with a positive result for the dichlorophenolindophenol precipitation (DCIP) screening test. After routine laboratory investigation, the female was diagnosed with heterozygous Hb E (HBB: c.79G>A) during pregnancy; however, the male, whose case we present herein, was suspected to carry a rare heterozygous ß-thalassemia (ß-thal). Therefore, they were designated as a couple at-risk for having a fetus with a serious thalassemia genotype: compound heterozygosity for Hb E with ß-thal (Hb E/ß-thal). Based on the result of the DCIP test, his DNA was sequenced for a causative mutation and revealed heterozygosity for a rare Hb variant, Hb Dhonburi. Theoretically, this couple was not at risk for Hb E/ß-thal. Furthermore, this case demonstrates for the first time that in addition to a common Hb variant, i.e. Hb E, Hb Dhonburi (Hb Neapolis) also gives positive DCIP results, even in the heterozygous state.


Subject(s)
Hemoglobins, Abnormal , beta-Thalassemia , 2,6-Dichloroindophenol , Female , Hemoglobins, Abnormal/genetics , Heterozygote , Humans , Male , Mutation , Pregnancy , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics
18.
Hemoglobin ; 46(3): 164-167, 2022 May.
Article in English | MEDLINE | ID: mdl-35543093

ABSTRACT

In children with ß-thalassemia (ß-thal) trait, tissue damage occurs with oxidative stress due to oxygen free radicals and reactive oxygen species (ROS) production. Dynamic thiol-disulfide homeostasis (DTDH) is one of the most important indicators showing the pro-oxidant/antioxidant status in the body. In this study, we aimed to examine the status of DTDH by measuring native thiol, disulfide, and total thiol levels in children with ß-thal trait. The study included 40 children with ß-thal trait and 30 healthy controls (matched by age and gender). The DTDH parameters were measured by an automated method and results were compared between the groups. The levels of native thiol, total thiol, and disulfide in children with ß-thal trait group were statistically significantly higher than the control group (p < 0.001). There was no significant difference in disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol levels between the groups. In addition, there was no correlation between hemoglobin (Hb) and serum ferritin levels with the markers of DTDH in children with ß-thal trait. In our study, a significant increase was found in native thiol, total thiol, and disulfide levels in response to oxidative stress in children with ß-thal trait compared to the healthy control group. Disulfide levels of the children with ß-thal trait were higher than the control group, showing oxidative stress is high in ß-thal trait. Accordingly, it increases the native thiol and total thiol capacity as compensation.


Subject(s)
Disulfides , beta-Thalassemia , Antioxidants , Biomarkers , Child , Disulfides/metabolism , Ferritins , Hemoglobins , Homeostasis/physiology , Humans , Oxidative Stress/physiology , Reactive Oxygen Species , Sulfhydryl Compounds
19.
Hemoglobin ; 46(4): 249-252, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35575165

ABSTRACT

ß-Thalassemia (ß-thal) is caused by mutations on the ß-globin genes, causing reduced (ß+) or absent (ß0) synthesis of the ß chains of hemoglobin (Hb). In this report, a 28-year-old male patient with anemia and jaundice, was diagnosed with triple-heterozygous ß-thal [an IVS-II-654 (C>T) mutation, a Hb Zürich-Langstrasse (HBB: c.151A>T) mutation and a Hb G-Siriraj (HBB: c.22G>A) mutation] by gene sequencing. However, his electrophoresis pattern was unusual: 90.8% Hb G-Siriraj, 5.9% Hb A2, 3.3% Hb F, no Hb A, no Hb Zürich-Langstrasse. His mother carried a ß-thal trait (ßA/ßIVS-II-654) having mild anemia, with a classical electrophoresis pattern (95.1% Hb A, 4.4% Hb A2, 0.5% Hb F). His father was heterozygous for Hb G-Siriraj (ßA/ßG-Siriraj) but asymptomatic, with a corresponding electrophoresis pattern (63.9% Hb A, 3.5% Hb A2, 32.6% Hb G-Siriraj). In view of the family study results, the Hb Zürich-Langstrasse mutation in the proband was considered a de novo mutation occurring on the ßIVS-II-654 allele that he inherited from his mother, resulting in a ßIVS-II-654/Hb Zürich-Langstrasse genotype, which should be interpreted as a novel ß0 mutation. This report illustrates that mutations in cis can confound genotype-phenotype correlations, therefore, just as DNA testing and Hb analysis, family study is also indispensable to the accurate identification of ß-thal mutations.


Subject(s)
beta-Thalassemia , Male , Humans , beta-Thalassemia/diagnosis , beta-Thalassemia/genetics , beta-Globins/genetics , Hemoglobin A2/genetics , Mutation , Genotype , Electrophoresis
20.
Hemoglobin ; 46(3): 168-175, 2022 May.
Article in English | MEDLINE | ID: mdl-35635444

ABSTRACT

In the already identified quantitative trait loci (QTL), modulating Hb F levels are cis-acting haplotypes of the ß-globin gene cluster itself, although the single nucleotide polymorphisms (SNPs) accounting more for the association, remain uncertain. In this study, the role in Hb F production of previously reported candidate SNPs within the ß-globin gene cluster was reexamined, along with a yet poorly studied variation in the BGLT3 gene. In a sample of ß-thalassemia (ß-thal) carriers, we succeeded in replicating the significant association between increased Hb F levels and rs7482144 (C>T) (HBG2 XmnI), which is the most well-established variation in the cluster influencing the trait. This SNP was found to be in strong linkage disequilibrium (LD) with a variation in the HBBP1 gene [rs10128556 (G>A)], which consistently revealed a similar association signal. Remarkably, much stronger than the latter associations were those involving both rs968857 (T allele) (3' HBBP1) and rs7924684 (G allele) (BGLT3), two SNPs that were also in strong LD. As the pattern of LD detected in the ß-globin gene cluster does not correlate with a tight linkage between markers, complex interactions between SNPs at the cluster seem to modulate Hb F. Seeing that no such associations were detected in normal subjects, the question can be raised on whether, under erythropoiesis stress, epigenetic mechanisms contribute to change the regulation of the entire ß-globin gene cluster. In conclusion, we provide statistical evidence for a new player within the ß-globin gene cluster, BGLT3, that in cooperation with other regions influences Hb F levels in ß-thal carriers.


Subject(s)
beta-Globins , beta-Thalassemia , Carrier Proteins/genetics , Fetal Hemoglobin/genetics , Humans , Multigene Family , Quantitative Trait Loci , beta-Globins/genetics , beta-Thalassemia/genetics
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