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Kirkham JK, Estepp JH, Weiss MJ, Rashkin SR. Genetic Variation and Sickle Cell Disease Severity: A Systematic Review and Meta-Analysis. JAMA Netw Open 2023; 6:e2337484. [PMID: 37851445 PMCID: PMC10585422 DOI: 10.1001/jamanetworkopen.2023.37484] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/30/2023] [Indexed: 10/19/2023] Open
Abstract
Importance Sickle cell disease (SCD) is a monogenic disorder, yet clinical outcomes are influenced by additional genetic factors. Despite decades of research, the genetics of SCD remain poorly understood. Objective To assess all reported genetic modifiers of SCD, evaluate the design of associated studies, and provide guidelines for future analyses according to modern genetic study recommendations. Data Sources PubMed, Web of Science, and Scopus were searched through May 16, 2023, identifying 5290 publications. Study Selection At least 2 reviewers identified 571 original, peer-reviewed English-language publications reporting genetic modifiers of human SCD phenotypes, wherein the outcome was not treatment response, and the comparison was not between SCD subtypes or including healthy controls. Data Extraction and Synthesis Data relevant to all genetic modifiers of SCD were extracted, evaluated, and presented following STREGA and PRISMA guidelines. Weighted z score meta-analyses and pathway analyses were conducted. Main Outcomes and Measures Outcomes were aggregated into 25 categories, grouped as acute complications, chronic conditions, hematologic parameters or biomarkers, and general or mixed measures of SCD severity. Results The 571 included studies reported on 29 670 unique individuals (50% ≤ 18 years of age) from 43 countries. Of the 17 757 extracted results (4890 significant) in 1552 genes, 3675 results met the study criteria for meta-analysis: reported phenotype and genotype, association size and direction, variability measure, sample size, and statistical test. Only 173 results for 62 associations could be cross-study combined. The remaining associations could not be aggregated because they were only reported once or methods (eg, study design, reporting practice) and genotype or phenotype definitions were insufficiently harmonized. Gene variants regulating fetal hemoglobin and α-thalassemia (important markers for SCD severity) were frequently identified: 19 single-nucleotide variants in BCL11A, HBS1L-MYB, and HBG2 were significantly associated with fetal hemoglobin (absolute value of Z = 4.00 to 20.66; P = 8.63 × 10-95 to 6.19 × 10-5), and α-thalassemia deletions were significantly associated with increased hemoglobin level and reduced risk of albuminuria, abnormal transcranial Doppler velocity, and stroke (absolute value of Z = 3.43 to 5.16; P = 2.42 × 10-7 to 6.00 × 10-4). However, other associations remain unconfirmed. Pathway analyses of significant genes highlighted the importance of cellular adhesion, inflammation, oxidative and toxic stress, and blood vessel regulation in SCD (23 of the top 25 Gene Ontology pathways involve these processes) and suggested future research areas. Conclusions and Relevance The findings of this comprehensive systematic review and meta-analysis of all published genetic modifiers of SCD indicated that implementation of standardized phenotypes, statistical methods, and reporting practices should accelerate discovery and validation of genetic modifiers and development of clinically actionable genetic profiles.
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Affiliation(s)
- Justin K. Kirkham
- Department of Oncology, St Jude Children’s Research Hospital, Memphis, Tennessee
| | - Jeremie H. Estepp
- Department of Hematology, St Jude Children’s Research Hospital, Memphis, Tennessee
- Department of Global Pediatric Medicine, St Jude Children’s Research Hospital, Memphis, Tennessee
- Now with Agios Pharmaceuticals, Cambridge, Massachusetts
| | - Mitch J. Weiss
- Department of Hematology, St Jude Children’s Research Hospital, Memphis, Tennessee
| | - Sara R. Rashkin
- Department of Hematology, St Jude Children’s Research Hospital, Memphis, Tennessee
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Hariharan P, Gorivale M, Sawant P, Mehta P, Nadkarni A. Significance of genetic modifiers of hemoglobinopathies leading towards precision medicine. Sci Rep 2021; 11:20906. [PMID: 34686692 PMCID: PMC8536722 DOI: 10.1038/s41598-021-00169-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 09/02/2021] [Indexed: 11/17/2022] Open
Abstract
Hemoglobinopathies though a monogenic disorder, show phenotypic variability. Hence, understanding the genetics underlying the heritable sub-phenotypes of hemoglobinopathies, specific to each population, would be prognostically useful and could inform personalized therapeutics. This study aimed to evaluate the role of genetic modifiers leading to higher HbF production with cumulative impact of the modifiers on disease severity. 200 patients (100 β-thalassemia homozygotes, 100 Sickle Cell Anemia), and 50 healthy controls were recruited. Primary screening followed with molecular analysis for confirming the β-hemoglobinopathy was performed. Co-existing α-thalassemia and the polymorphisms located in 3 genetic loci linked to HbF regulation were screened. The most remarkable result was the association of SNPs with clinically relevant phenotypic groups. The γ-globin gene promoter polymorphisms [- 158 C → T, + 25 G → A],BCL11A rs1427407 G → T, - 3 bp HBS1L-MYB rs66650371 and rs9399137 T → C polymorphisms were correlated with higher HbF, in group that has lower disease severity score (P < 0.00001), milder clinical presentation, and a significant delay in the age of the first transfusion. Our study emphasizes the complex genetic interactions underlying the disease phenotype that may be a prognostic marker for predicting the clinical severity and assist in disease management.
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Affiliation(s)
- Priya Hariharan
- Department of Haematogenetics, ICMR-National Institute of Immunohaematology, 13th Floor NMS Building, KEM Hospital Campus, Parel, Mumbai, 400012, India
| | - Manju Gorivale
- Department of Haematogenetics, ICMR-National Institute of Immunohaematology, 13th Floor NMS Building, KEM Hospital Campus, Parel, Mumbai, 400012, India
| | - Pratibha Sawant
- Department of Haematogenetics, ICMR-National Institute of Immunohaematology, 13th Floor NMS Building, KEM Hospital Campus, Parel, Mumbai, 400012, India
| | - Pallavi Mehta
- Department of Haematogenetics, ICMR-National Institute of Immunohaematology, 13th Floor NMS Building, KEM Hospital Campus, Parel, Mumbai, 400012, India
| | - Anita Nadkarni
- Department of Haematogenetics, ICMR-National Institute of Immunohaematology, 13th Floor NMS Building, KEM Hospital Campus, Parel, Mumbai, 400012, India.
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Lakkakula BVKS, Pattnaik S. The HBG2 rs7482144 (C > T) Polymorphism is Linked to HbF Levels but not to the Severity of Sickle Cell Anemia. J Pediatr Genet 2021; 12:129-134. [PMID: 37090825 PMCID: PMC10118708 DOI: 10.1055/s-0041-1733950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/08/2021] [Indexed: 12/23/2022]
Abstract
AbstractSickle cell anemia (SCA) is a severe disease characterized by anemia, acute clinical complications, and a relatively short life span. In this disease, abnormal hemoglobin makes the red blood cells deformed, rigid, and sticky. Fetal hemoglobin (HbF) is one of the key modulators of SCA morbidity and mortality. Interindividual HbF variation is a heritable trait that is controlled by polymorphism in genes linked and unlinked to the hemoglobin β gene (HBB). The genetic polymorphisms that determine HbF levels are known to ameliorate acute clinical events. About 190 well-characterized homozygous SCA patients were included in this study. Complete blood count (CBC), high-performance liquid chromatography (HPLC), and clinical investigations were obtained from patient's records. Severity scores were determined by using the combination of anemia, complications, total leucocyte count, and transfusion scores. HBG2 rs7482144 polymorphism was genotyped by using the polymerase chain reaction and restriction fragment length polymorphism. The association between HBG2 rs7482144 polymorphism and HbF levels as well as the disease severity of SCA were assessed. SCA patients carrying TT genotype were found to have higher HbF levels. In addition, SCA patients with increased severity showed significantly lower levels of hemoglobin, HbF, and hematocrit values. However, the genotypes of HBG2 rs7482144 polymorphism were not found to be associated with the risk of disease severity. In summary, this study demonstrated that HBG2 rs7482144 polymorphism is linked with HbF levels, but it does not affect disease severity. The sample sizes used and the pattern of association deduced from our small sample size prevents us from extrapolating our findings further.
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Affiliation(s)
| | - Smaranika Pattnaik
- Department of Biotechnology and Bioinformatics, Sambalpur University, Sambalpur, Odisha, India
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Verma HK, Ratre YK, Bhaskar LVKS, Colombatti R. Erythrocyte microRNAs: a tiny magic bullet with great potential for sickle cell disease therapy. Ann Hematol 2021; 100:607-614. [PMID: 33398452 DOI: 10.1007/s00277-020-04390-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/21/2020] [Indexed: 12/11/2022]
Abstract
Sickle cell disease (SCD) is a severe hereditary blood disorder caused by a mutation of the beta-globin gene, which results in a substantial reduction in life expectancy. Many studies are focused on various novel therapeutic strategies that include re-activation of the γ-globin gene. Among them, expression therapy caused by the fetal hemoglobin (HbF) at a later age is highly successful. The induction of HbF is one of the dominant genetic modulators of the hematological and clinical characteristics of SCD. In fact, HbF compensates for the abnormal beta chain and has an ameliorant effect on clinical complications. Erythropoiesis is a multi-step process that involves the proliferation and differentiation of a small population of hematopoietic stem cells and is affected by several factors, including signaling pathways, transcription factors, and small non-coding RNAs (miRNAs). miRNAs play a regulatory role through complex networks that control several epigenetic mechanisms as well as the post-transcriptional regulation of multiple genes. In this review, we briefly describe the current understanding of interactions between miRNAs, their molecular targets, and their regulatory effects in HbF induction in SCD.
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Affiliation(s)
- Henu Kumar Verma
- Institute of Endocrinology and Oncology CNR, 83031, Naples, Italy.
| | - Yashwant Kumar Ratre
- Department of Biotechnology, Guru Ghasidas Vishwavidyalaya, Bilaspur, 495009, India
| | - L V K S Bhaskar
- Department of Zoology, Guru Ghasidas Vishwavidyalaya, Bilaspur, 495009, India
| | - Raffaella Colombatti
- Clinic of Pediatric Hematology Oncology, Department of Woman's and Child's Health, University of Padova, Via Giustiniani 3, 35128, Padova, Italy
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Verma HK, Swarnakar S, L.V.K.S. B. Genetic association of GSTM1, GSTT1, and GSTP1 polymorphisms with sickle cell disease complications: A systematic review and meta-analysis. Meta Gene 2020; 26:100815. [DOI: 10.1016/j.mgene.2020.100815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Qadah T, Noorwali A, Alzahrani F, Banjar A, Filimban N, Felimban R. Detection of BCL11A and HBS1L-MYB Genotypes in Sickle Cell Anemia. Indian J Hematol Blood Transfus 2020; 36:705-710. [PMID: 33100714 DOI: 10.1007/s12288-020-01270-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/22/2020] [Indexed: 11/25/2022] Open
Abstract
Sickle Cell Anemia (SCA) is one of the most common monogenic disorders worldwide. Molecular modifiers of clinical symptoms play an essential role in the amelioration of the effects of the disease. Single Nucleotide Polymorphisms (SNPs) of the BCL11A gene and within the HBS1L-MYB intergenic region, which are located outside the β-globin locus on chromosome 11, are considered to be genetic modifiers that are associated with elevated levels of foetal haemoglobin HbF, and thus they reduce the clinical impact of sickle haemoglobin, HbS. The work reported here aimed to detect the most common SNPs of BCL11A and HBS1L-MYB related to HbF in SCA patients and to estimate the frequency of occurrence of these genotypes. A total of 132 SCA patients whose condition was stable were recruited from Jeddah city, Saudi Arabia. SNPs at site locus rs4671393 on BCL11A, and at loci rs28384513 and rs9399137 on HBS1L-MYB were identified using TaqMan genotyping assay. Haematological parameters were analysed based on complete blood count and haemoglobin separation using the capillary electrophoresis technique. Highly significant differences in the diagnostic haematological parameters, including all blood-cell types and HbF, were observed between the study cohort and control groups. We also found that BCL11A rs4671393 genotypes of GG and AG were more likely to show increases in HbF levels than other genotypes. In addition, a strong relationship was found between HBS1L-MYB rs9399137 and rs28384513 genotypes in the cohort, whereas no significant association was observed between BCL11A rs4671393 variant and other variants. Our study highlights the importance of investigating genetic determinants that play roles in the amelioration of the severity of clinical symptoms and complications of SCA.
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Affiliation(s)
- Talal Qadah
- Regenerative Medicine Unit, King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box: 80324, Jeddah, 21589 Saudi Arabia
| | - Abdulwahab Noorwali
- Regenerative Medicine Unit, King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Fatma Alzahrani
- Department of Pediatrics, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Alaa Banjar
- Regenerative Medicine Unit, King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box: 80324, Jeddah, 21589 Saudi Arabia
| | - Najlaa Filimban
- Regenerative Medicine Unit, King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Raed Felimban
- Regenerative Medicine Unit, King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box: 80324, Jeddah, 21589 Saudi Arabia
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BCL11A: a potential diagnostic biomarker and therapeutic target in human diseases. Biosci Rep 2020; 39:220893. [PMID: 31654056 PMCID: PMC6851505 DOI: 10.1042/bsr20190604] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/16/2022] Open
Abstract
Transcription factor B-cell lymphoma/leukemia 11A (BCL11A) gene encodes a zinc-finger protein that is predominantly expressed in brain and hematopoietic tissue. BCL11A functions mainly as a transcriptional repressor that is crucial in brain, hematopoietic system development, as well as fetal-to-adult hemoglobin switching. The expression of this gene is regulated by microRNAs, transcription factors and genetic variations. A number of studies have recently shown that BCL11A is involved in β-hemoglobinopathies, hematological malignancies, malignant solid tumors, 2p15-p16.1 microdeletion syndrome, and Type II diabetes. It has been suggested that BCL11A may be a potential prognostic biomarker and therapeutic target for some diseases. In this review, we summarize the current research state of BCL11A, including its biochemistry, expression, regulation, function, and its possible clinical application in human diseases.
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Darshana T, Bandara D, Nawarathne U, de Silva U, Costa Y, Pushpakumara K, Pathirage S, Basnayake S, Epa C, Dilrukshi P, Wijayawardena M, Anthony AA, Rodrigo R, Manamperi A, Smith F, Allen A, Menzel S, Rees D, Premawardhena A. Sickle cell disease in Sri Lanka: clinical and molecular basis and the unanswered questions about disease severity. Orphanet J Rare Dis 2020; 15:177. [PMID: 32631379 PMCID: PMC7339547 DOI: 10.1186/s13023-020-01458-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 06/29/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Though case reports and limited case series of Sickle cell disease in Sri Lanka have been reported previously, no attempt has been made hitherto to undertake a comprehensive genotypic-phenotypic analysis of this "rare" group of patients. RESULTS All accessible Sickle cell disease patients, totaling 60, including, 51 Sickle β-thalassaemia and 9 homozygous sickle patients were enrolled from seven thalassaemia treatment centres between December 2016-March 2019. The majority of patients were of Sinhalese ethnicity (n = 52, 86.67%). Geographically, two prominent clusters were identified and the distribution of Sickle haemoglobin in the island contrasted markedly with the other haemoglobinopathies. 3/ 9 homozygous sickle patients and 3/ 51 Sickle β-thalassaemia patients were receiving regular transfusion. Joint pain was the commonest clinical symptom among all sickle cell disease patients (n = 39, 65.0%). Dactylitis was significantly more common in homozygous sickle patients compared with the Sickle β-thalassaemia groups (p 0.027). Two genetic backgrounds sickle mutation were identified namely, Arab Indian and Benin. Among the regulators of Foetal hemoglobin in Sickle patients of the present study rs1427407 G > T seemed to be the most prominent modifier, with a significant association with Foetal haemoglobin levels (p 0.04). CONCLUSIONS Overall, the clinical course of the Asian version of Sickle cell disease in Sri Lanka appears to be milder than that described in India.
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Affiliation(s)
- Thamal Darshana
- Department of Medical Laboratory Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
| | - Dayananda Bandara
- National Thalassaemia Centre, Teaching Hospital, Kurunegala, Sri Lanka
| | - Upul Nawarathne
- Department of Pediatrics, Teaching Hospital, Kurunegala, Sri Lanka
| | - Udaya de Silva
- Thalassaemia Unit, Teaching Hospital, Anuradhapura, Sri Lanka
| | - Yasinta Costa
- Department of Haematology, Teaching Hospital, Ragama, Sri Lanka
| | | | - Sumithra Pathirage
- Department of Pediatrics, District General Hospital, Hambantota, Sri Lanka
| | - Seuwandi Basnayake
- Department of Haematology, District General Hospital, Monaragala, Sri Lanka
| | - Chamila Epa
- Department of Haematology, Teaching Hospital, Batticaloa, Sri Lanka
| | | | | | - Angela A Anthony
- Department of Clinical Sciences, Eastern University, Batticaloa, Sri Lanka
| | - Rexan Rodrigo
- Thalassaemia Adult and Adolescent Care Centre, Teaching Hospital, Ragama, Sri Lanka
| | - Aresha Manamperi
- Molecular Medicine Unit, University of Kelaniya, Ragama, Sri Lanka
| | - Frances Smith
- Molecular Pathology Department, Viapath at King's College Hospital, London, UK
| | - Angela Allen
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Stephan Menzel
- School of Cancer and Pharmaceutical Sciences, The Rayne Institute, King's College London, London, UK
| | - David Rees
- Department of Haematological Medicine, King's College Hospital, London, UK
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Hassan FM, Al-Zahrani FM. BCL11A rs1427407 Genotypes in Sickle Cell Anemia Patients Undergo to Stroke Problems in Sudan. Korean J Fam Med 2018; 40:53-57. [PMID: 30563311 PMCID: PMC6351796 DOI: 10.4082/kjfm.17.0144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/16/2018] [Indexed: 11/24/2022] Open
Abstract
Background Sickle cell disease is an autosomal recessive condition that results from the presence of a mutated form of hemoglobin. Some genetic variants of BCL11A are amenable to therapeutic manipulation. The present study investigated the relationship of a BCL11A variant (rs1427407) and its plasma levels with vaso-occlusive crises and stroke complications among patients in Sudan with sickle cell disease. Methods This cross-sectional study was performed between June 2014 and October 2016. The subjects included 166 patients who were diagnosed with sickle cell disease and 35 healthy control subjects, who were grouped according to sex and age (<15 years, 15–25 years, and >25 years). All patients and/or their guardians provided informed consent. Blood samples were collected from the patients and controls under aseptic conditions. Results Plasma BCL11A levels were elevated in cases with vaso-occlusive crises that lasted for >3 years. In addition, plasma BCL11A levels were high in cases with the GG genotype (vs. GT and TT) at rs1427407. Furthermore, the BCL11A rs1427407 GG/GT genotypes increased the risk of vaso-occlusive crisis and stroke in the patients with sickle cell disease. Conclusion The BCL11A variant (rs1427407) and its plasma levels were associated with vaso-occlusive crisis and stroke in patients with sickle cell disease.
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Affiliation(s)
- Fathelrahman Mahdi Hassan
- Department of Clinical Laboratory Science, College of Applied Medical Science, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Faisal Mousa Al-Zahrani
- Department of Clinical Laboratory Science, College of Applied Medical Science, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Al-Allawi N, Qadir SMA, Puehringer H, Chui DHK, Farrell JJ, Oberkanins C. The association of HBG2, BCL11A, and HMIP polymorphisms with fetal hemoglobin and clinical phenotype in Iraqi Kurds with sickle cell disease. Int J Lab Hematol 2018; 41:87-93. [PMID: 30216683 DOI: 10.1111/ijlh.12927] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/14/2018] [Accepted: 08/14/2018] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Fetal hemoglobin (HbF) is the major modifier for sickle cell disease (SCD) severity. HbF is modulated mainly by three major quantitative trait loci (QTL) on chromosomes 2, 6, and 11. METHODS Five SNPs in the three QTLs (HBG2, rs7482144; BCL11A, rs1427407 and rs10189857; and HBS1L-MYB intergenic region, rs28384513 and rs9399137) were investigated by multiplex PCR and reverse hybridization, and their roles in HbF and clinical phenotype variability in Iraqi Kurds with SCD were assessed. RESULTS HBG2 rs7482144 with minor allele frequency (MAF) of 0.133 was the most significant contributor to HbF variability, contributing 18.1%, followed by rs1427407 (MAF of 0.266) and rs9399137 (MAF of 0.137) at 14.3% and 8.8%, respectively. The other two SNPs were not significant contributors. Furthermore, when the cumulative numbers of minor alleles in the three contributing SNPs were assessed, HbF% and hemoglobin concentration increased with increasing number of minor alleles (P < 0.0005 and 0.001, respectively), while serum lactic dehydrogenase, reticulocytes, leukocytes, transfusion, and pain frequencies decreased (P = 0.003, 0.004, <0.0005, <0.0005, and 0.017, respectively). CONCLUSIONS It was demonstrated that SNPs in all three major HbF QTLs contribute significantly to HbF and clinical variability in Iraqi Kurds with SCD and that the cumulative number of minor alleles at contributing SNPs may serve as a better predictor of such variability in this population.
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Affiliation(s)
- Nasir Al-Allawi
- Department of Pathology, College of Medicine, University of Duhok, Duhok, Iraq
| | | | | | - David H K Chui
- Departments of Medicine, Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts
| | - John J Farrell
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, Massachusetts
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Bhanushali AA, Himani K, Patra PK, Das BR. Hb F Levels in Indian Sickle Cell Patients and Association with the HBB Locus Variant rs10128556 (C>T), and the HBG XmnI (Arab-Indian) Variant. Hemoglobin 2018; 41:317-320. [DOI: 10.1080/03630269.2017.1414059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Kumari Himani
- Research and Development, SRL Ltd., Goregaon (W), Mumbai, India
| | - Pradeep K. Patra
- Department of Biochemistry, Pandit Jawaharlal Nehru Memorial Medical College, Raipur, Chhattisgarh, India
| | - Bibhu R. Das
- Research and Development, SRL Ltd., Goregaon (W), Mumbai, India
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Serjeant GR, Vichinsky E. Variability of homozygous sickle cell disease: The role of alpha and beta globin chain variation and other factors. Blood Cells Mol Dis 2017; 70:66-77. [PMID: 28689691 DOI: 10.1016/j.bcmd.2017.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 06/10/2017] [Accepted: 06/19/2017] [Indexed: 12/11/2022]
Abstract
The single base molecular substitution characterizing sickle cell haemoglobin, β6glu→val, might be expected to result in predictable haematological and clinical features. However, the disease manifests remarkable diversity believed to reflect the interaction with other genetic and environmental factors. Some of the genetic modifiers include the beta globin haplotypes, alpha thalassaemia, factors influencing the persistence of fetal haemoglobin and the effects of the environment are addressed in this review. It is concluded that much of the genetic data present conflicting results. Environmental factors such as climate and infections, and psychological, educational and social support mechanisms also influence expression of the disease. These interactions illustrate how the expression of a 'single gene' disorder may be influenced by a variety of other genetic and environmental factors.
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Affiliation(s)
- Graham R Serjeant
- Sickle Cell Trust (Jamaica), 14 Milverton Crescent, Kingston 6, Jamaica.
| | - Elliott Vichinsky
- Hematology/Oncology, UCSF Benioff Children's Hospital Oakland, University of California San Francisco, 747 52nd Street, Oakland, CA 94609, United States.
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Influence of single nucleotide polymorphisms in the BCL11A and HBS1L-MYB gene on the HbF levels and clinical severity of sickle cell anaemia patients. Ann Hematol 2016; 95:1201-3. [DOI: 10.1007/s00277-016-2675-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 04/13/2016] [Indexed: 11/26/2022]
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