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Liang G, Lin Z, Zhang Y, Zhang Q, Zhu D, Liang X, Xie H, Wei X, Shang X. Precise diagnosis of a hereditary spherocytosis patient with complicated hematological phenotype. Mol Genet Genomics 2024; 299:57. [PMID: 38787432 DOI: 10.1007/s00438-024-02150-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Hereditary spherocytosis (HS) is one of the most common causes of hereditary hemolytic anemia. The current diagnostic guidelines for HS are mainly based on a combination of physical examination and laboratory investigation. However, some patients present with complicated clinical manifestations that cannot be explained by routine diagnostic protocols. Here, we report a rare HS case of mild anemia with extremely high indirect bilirubin levels and high expression of fetal hemoglobin. Using whole exome sequencing analysis, this patient was identified as a heterozygous carrier of a de novo SPTB nonsense mutation (c.605G > A; p.W202*) and a compound heterozygous carrier of known UGT1A1 and KLF1 mutations. This genetic analysis based on the interpretation of the patient's genomic data not only achieved precise diagnosis by an excellent explanation of the complicated phenotype but also provided valuable suggestions for subsequent appropriate approaches for treatment, surveillance and prophylaxis.
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Affiliation(s)
- Guanxia Liang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Zezhang Lin
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yang Zhang
- Department of Basic medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Qianqian Zhang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Dina Zhu
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiongda Liang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Hongting Xie
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiaofeng Wei
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xuan Shang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
- Innovation Center for Diagnostics and Treatment of Thalassemia, Nanfang Hospital, Southern Medical University, Guangzhou, China.
- Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
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Ye L, Wang C, Li A, Li M, Pi Y, Yang J, Zhu Z, Lu D. Targeted next-generation sequencing and long-read HiFi sequencing provide novel insights into clinically significant KLF1 variants. BMC Genomics 2024; 25:230. [PMID: 38429690 PMCID: PMC10908068 DOI: 10.1186/s12864-024-10148-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 02/20/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND Krüppel-like factor 1 (KLF1), a crucial erythroid transcription factor, plays a significant role in various erythroid changes and haemolytic diseases. The rare erythrocyte Lutheran inhibitor (In(Lu)) blood group phenotype serves as an effective model for identifying KLF1 hypomorphic and loss-of-function variants. In this study, we aimed to analyse the genetic background of the In(Lu) phenotype in a population-based sample group by high-throughput technologies to find potentially clinically significant KLF1 variants. RESULTS We included 62 samples with In(Lu) phenotype, screened from over 300,000 Chinese blood donors. Among them, 36 samples were sequenced using targeted Next Generation Sequencing (NGS), whereas 19 samples were sequenced using High Fidelity (HiFi) technology. In addition, seven samples were simply sequenced using Sanger sequencing. A total of 29 hypomorphic or loss-of-function variants of KLF1 were identified, 21 of which were newly discovered. All new variants discovered by targeted NGS or HiFi sequencing were validated through Sanger sequencing, and the obtained results were found to be consistent. The KLF1 haplotypes of all new variants were further confirmed using clone sequencing or HiFi sequencing. The lack of functional KLF1 variants detected in the four samples indicates the presence of additional regulatory mechanisms. In addition, some samples exhibited BCAM polymorphisms, which encodes antigens of the Lutheran (LU) blood group system. However, no BCAM mutations which leads to the absence of LU proteins were detected. CONCLUSIONS High-throughput sequencing methods, particularly HiFi sequencing, were introduced for the first time into genetic analysis of the In(Lu) phenotype. Targeted NGS and HiFi sequencing demonstrated the accuracy of the results, providing additional advantages such as simultaneous analysis of other blood group genes and clarification of haplotypes. Using the In(Lu) phenotype, a powerful model for identifying hypomorphic or loss-of-function KLF1 variants, numerous novel variants have been detected, which have contributed to the comprehensive understanding of KLF1. These clinically significant KLF1 mutations can serve as a valuable reference for the diagnosis of related blood cell diseases.
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Affiliation(s)
- Luyi Ye
- State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, 200433, Shanghai, China
- Shanghai Institute of Blood Transfusion, Shanghai Blood Center, 20051, Shanghai, China
| | - Chen Wang
- Shanghai Institute of Blood Transfusion, Shanghai Blood Center, 20051, Shanghai, China
| | - Aijing Li
- Shanghai Institute of Blood Transfusion, Shanghai Blood Center, 20051, Shanghai, China
| | - Minghao Li
- Shanghai Institute of Blood Transfusion, Shanghai Blood Center, 20051, Shanghai, China
| | - Yan Pi
- State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, 200433, Shanghai, China
- NHC Key Laboratory of Birth Defects and Reproductive Health (Chongqing Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute), 400020, Chongqing, China
| | - Jingmin Yang
- State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, 200433, Shanghai, China
- Shanghai WeHealth Biomedical Technology Co., Ltd, 201318, Shanghai, China
| | - Ziyan Zhu
- Shanghai Institute of Blood Transfusion, Shanghai Blood Center, 20051, Shanghai, China
| | - Daru Lu
- State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, 200433, Shanghai, China.
- NHC Key Laboratory of Birth Defects and Reproductive Health (Chongqing Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute), 400020, Chongqing, China.
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Yuce K, Ozkan AI. The kruppel-like factor (KLF) family, diseases, and physiological events. Gene 2024; 895:148027. [PMID: 38000704 DOI: 10.1016/j.gene.2023.148027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 11/06/2023] [Accepted: 11/21/2023] [Indexed: 11/26/2023]
Abstract
The Kruppel-Like Factor family of regulatory proteins, which has 18 members, is transcription factors. This family contains zinc finger proteins, regulates the activation and suppression of transcription, and binds to DNA, RNA, and proteins. Klfs related to the immune system are Klf1, Klf2, Klf3, Klf4, Klf6, and Klf14. Klfs related to adipose tissue development and/or glucose metabolism are Klf3, Klf7, Klf9, Klf10, Klf11, Klf14, Klf15, and Klf16. Klfs related to cancer are Klf3, Klf4, Klf5, Klf6, Klf7, Klf8, Klf9, Klf10, Klf11, Klf12, Klf13, Klf14, Klf16, and Klf17. Klfs related to the cardiovascular system are Klf4, Klf5, Klf10, Klf13, Klf14, and Klf15. Klfs related to the nervous system are Klf4, Klf7, Klf8, and Klf9. Klfs are associated with diseases such as carcinogenesis, oxidative stress, diabetes, liver fibrosis, thalassemia, and the metabolic syndrome. The aim of this review is to provide information about the relationship of Klfs with some diseases and physiological events and to guide future studies.
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Affiliation(s)
- Kemal Yuce
- Selcuk University, Medicine Faculty, Department of Basic Medical Sciences, Physiology, Konya, Turkiye.
| | - Ahmet Ismail Ozkan
- Artvin Coruh University, Medicinal-Aromatic Plants Application and Research Center, Artvin, Turkiye.
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Chin H, Benton MC, Yang L, Poon KS, Tan KML, Jamuar SS, Foo R, Law HY, Goh DL, Chong SS, de Sessions PF. Clinical application of targeted long read sequencing in prenatal beta-thalassemia testing and genetic counseling. Mol Genet Genomic Med 2024; 12:e2285. [PMID: 37740604 PMCID: PMC10767580 DOI: 10.1002/mgg3.2285] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 08/18/2023] [Accepted: 09/07/2023] [Indexed: 09/24/2023] Open
Abstract
BACKGROUND Beta thalassemia, related to HBB mutation and associated with elevated hemoglobin A2 (HbA2), is an important genetic hemoglobinopathy with high incidences of disease and carrier rates in Singapore. Carrier screening is essential to facilitate prenatal counseling and testing. However, when individuals with elevated HbA2 do not have an identifiable HBB disease-associated variant, there is ambiguity on risk to their offspring. METHODS We describe a case report of a proband with elevated HbA2, no identifiable HBB disease-associated variant, whose partner was a beta thalassemia carrier. Through clinical HBB gene sequencing, multiplex ligation-dependent probe amplification (MLPA) analysis, as well as targeted Nanopore long read sequencing of selected genes, we performed a complete analysis of HBB including the promoter region, 5'UTR and coding gene sequence, as well as evaluation for potential modifier variants and other rare structural variants. RESULTS This process identified that the proband was heterozygous for KLF1:c.544T>C (p.Phe182Leu), a potential functional polymorphism previously known to be associated with benign elevated HbA2 levels. The presence of disease variants in the HBB locus was excluded. CONCLUSION This finding provided clarity and enabled family planning for the proband and her family.
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Affiliation(s)
- Hui‐Lin Chin
- Division of Genetics and Metabolism, Department of PaediatricsKhoo Teck Puat‐National University Children's Medical Institute, National University HospitalSingaporeSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
| | | | - Lin Yang
- Oxford Nanopore TechnologiesSingaporeSingapore
| | - Kok Siong Poon
- Department of Laboratory MedicineNational University HospitalSingaporeSingapore
| | - Karen M. L. Tan
- Department of Laboratory MedicineNational University HospitalSingaporeSingapore
| | - Saumya S. Jamuar
- Genetics Service, Department of PaediatricsKK Women's and Children's HospitalSingaporeSingapore
| | - Roger Foo
- Cardiovascular Research Institute, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
| | - Hai Yang Law
- DNA Diagnostic and Research LaboratoryKK Women's and Children's HospitalSingaporeSingapore
| | - Denise Li‐Meng Goh
- Division of Genetics and Metabolism, Department of PaediatricsKhoo Teck Puat‐National University Children's Medical Institute, National University HospitalSingaporeSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
| | - Samuel S. Chong
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Department of Laboratory MedicineNational University HospitalSingaporeSingapore
- Department of Obstetrics and GynaecologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
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Catapano R, Sessa R, Trombetti S, Cesaro E, Russo F, Izzo P, Makis A, Grosso M. Identification and Functional Analysis of Known and New Mutations in the Transcription Factor KLF1 Linked with β-Thalassemia-like Phenotypes. BIOLOGY 2023; 12:biology12040510. [PMID: 37106711 PMCID: PMC10135830 DOI: 10.3390/biology12040510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/31/2023]
Abstract
The erythroid transcriptional factor Krüppel-like factor 1 (KLF1) is a master regulator of erythropoiesis. Mutations that cause KLF1 haploinsufficiency have been linked to increased fetal hemoglobin (HbF) and hemoglobin A2 (HbA2) levels with ameliorative effects on the severity of β-thalassemia. With the aim of determining if KLF1 gene variations might play a role in the modulation of β-thalassemia, in this study we screened 17 subjects showing a β-thalassemia-like phenotype with a slight or marked increase in HbA2 and HbF levels. Overall, seven KLF1 gene variants were identified, of which two were novel. Functional studies were performed in K562 cells to clarify the pathogenic significance of these mutations. Our study confirmed the ameliorative effect on the thalassemia phenotype for some of these variants but also raised the notion that certain mutations may have deteriorating effects by increasing KLF1 expression levels or enhancing its transcriptional activity. Our results indicate that functional studies are required to evaluate the possible effects of KLF1 mutations, particularly in the case of the co-existence of two or more mutations that could differently contribute to KLF1 expression or transcriptional activity and consequently to the thalassemia phenotype.
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Affiliation(s)
- Rosa Catapano
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Raffaele Sessa
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Silvia Trombetti
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, 80137 Naples, Italy
| | - Elena Cesaro
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Filippo Russo
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Paola Izzo
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Alexandros Makis
- Department of Pediatrics, University Hospital of Ioannina, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Michela Grosso
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
- Correspondence:
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Impact of Genetic Polymorphisms in Modifier Genes in Determining Fetal Hemoglobin Levels in Beta-Thalassemia. THALASSEMIA REPORTS 2023. [DOI: 10.3390/thalassrep13010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023] Open
Abstract
Genetic polymorphisms in Quantitative Trait Loci (QTL) genes such as BCL11A, HBS1L-MYB and KLF1 have been reported to influence fetal hemoglobin (HbF) levels. This prospective study was planned to evaluate the role of genetic polymorphisms in QTL genes as determinant of HbF levels in beta thalassemia major patients. The study was carried out on 100 thalassemia major patients. Blood samples were collected in EDTA and plain vials for biochemical and molecular evaluation. The BCL11A, HBS1L-MYB and KLF1 genotypes were determined using a polymerase chain reaction (PCR)-based method. Red Blood Cell (RBC) indices and HbF levels were assessed. In silico analysis was assessed using loss-of-function tool (Lof Tool). Statistical difference and genetic comparisons between groups were evaluated by using SPSS for Windows, version 16.0 (SPSS Inc., Chicago, IL, USA). Comparisons between quantitative variables were carried out after data explored for normality using Kolmogorov–Smirnov test of normality. Logistic regression was used for computation of ORs and 95% CIs (Confidence Interval). We observed association of HbF levels in thalassemia major patients with the polymorphisms in BCL11A (rs11886868 rs7557939; rs1427407 and rs766432) and HBS1L-MYB (rs9399137) gene. The results of this study indicated that the presence of polymorphisms on modifier genes are strongly associated with an increase in HbF levels in thalassemia major patients. Further research with a larger sample size and with other genes of modifier genes is required.
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Krüppel-Like Factor 1: A Pivotal Gene Regulator in Erythropoiesis. Cells 2022; 11:cells11193069. [PMID: 36231031 PMCID: PMC9561966 DOI: 10.3390/cells11193069] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Krüppel-like factor 1 (KLF1) plays a crucial role in erythropoiesis. In-depth studies conducted on mice and humans have highlighted its importance in erythroid lineage commitment, terminal erythropoiesis progression and the switching of globin genes from γ to β. The role of KLF1 in haemoglobin switching is exerted by the direct activation of β-globin gene and by the silencing of γ-globin through activation of BCL11A, an important γ-globin gene repressor. The link between KLF1 and γ-globin silencing identifies this transcription factor as a possible therapeutic target for β-hemoglobinopathies. Moreover, several mutations have been identified in the human genes that are responsible for various benign phenotypes and erythroid disorders. The study of the phenotype associated with each mutation has greatly contributed to the current understanding of the complex role of KLF1 in erythropoiesis. This review will focus on some of the principal functions of KLF1 on erythroid cell commitment and differentiation, spanning from primitive to definitive erythropoiesis. The fundamental role of KLF1 in haemoglobin switching will be also highlighted. Finally, an overview of the principal human mutations and relative phenotypes and disorders will be described.
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8
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Significance of borderline HbA 2 levels in β thalassemia carrier screening. Sci Rep 2022; 12:5414. [PMID: 35354866 PMCID: PMC8969165 DOI: 10.1038/s41598-022-09250-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/21/2022] [Indexed: 11/18/2022] Open
Abstract
Increased HbA2 levels are the characteristic feature of β-thalassemia carriers. A subset of carriers however do not show HbA2 levels in the typical carrier range (≥ 4.0%) but show borderline HbA2 levels. As a result, these carriers escape diagnosis and carry the risk of having β-thalassemia major offspring. Borderline HbA2 values may occur as a consequence of mild β-thalassemia mutations, co-inherited β-thalassemia and α- or δ- thalassemia or iron deficiency anemia. However, there is insufficient knowledge regarding the cause of borderline HbA2 levels in specific populations. This study aimed to identify the determinants of borderline HbA2 levels (which we have considered as HbA2 3.0–3.9%) in 205 individuals. Primary screening involved detecting the presence of iron deficiency anemia followed by molecular analysis of α, β and δ globin genes. Remarkably, 168 of 205 individuals were positive for a defect. 87% (149/168) of positive individuals were heterozygous for β thalassemia with (59/149) or without (90/149) the presence of co-existing IDA, α or δ gene defects. Notably, 20 of 149 β thalassemia carriers showed HbA2 < 3.5% and MCV > 80fL. 7 of these 20 carriers were married to carriers of hemoglobinopathies. Our findings describe the genetic basis of borderline HbA2 levels and emphasize the necessity of a molecular diagnosis in these individuals in the routine clinical setting.
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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: 2.7] [Reference Citation Analysis] [Abstract] [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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Huang L, Qiao Y, Xu W, Gong L, He R, Qi W, Gao Q, Cai H, Grossart HP, Yan Q. Full-Length Transcriptome: A Reliable Alternative for Single-Cell RNA-Seq Analysis in the Spleen of Teleost Without Reference Genome. Front Immunol 2021; 12:737332. [PMID: 34646272 PMCID: PMC8502891 DOI: 10.3389/fimmu.2021.737332] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/10/2021] [Indexed: 12/12/2022] Open
Abstract
Fish is considered as a supreme model for clarifying the evolution and regulatory mechanism of vertebrate immunity. However, the knowledge of distinct immune cell populations in fish is still limited, and further development of techniques advancing the identification of fish immune cell populations and their functions are required. Single cell RNA-seq (scRNA-seq) has provided a new approach for effective in-depth identification and characterization of cell subpopulations. Current approaches for scRNA-seq data analysis usually rely on comparison with a reference genome and hence are not suited for samples without any reference genome, which is currently very common in fish research. Here, we present an alternative, i.e. scRNA-seq data analysis with a full-length transcriptome as a reference, and evaluate this approach on samples from Epinephelus coioides-a teleost without any published genome. We show that it reconstructs well most of the present transcripts in the scRNA-seq data achieving a sensitivity equivalent to approaches relying on genome alignments of related species. Based on cell heterogeneity and known markers, we characterized four cell types: T cells, B cells, monocytes/macrophages (Mo/MΦ) and NCC (non-specific cytotoxic cells). Further analysis indicated the presence of two subsets of Mo/MΦ including M1 and M2 type, as well as four subsets in B cells, i.e. mature B cells, immature B cells, pre B cells and early-pre B cells. Our research will provide new clues for understanding biological characteristics, development and function of immune cell populations of teleost. Furthermore, our approach provides a reliable alternative for scRNA-seq data analysis in teleost for which no reference genome is currently available.
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Affiliation(s)
- Lixing Huang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Ying Qiao
- Fourth Institute of Oceanography, Ministry of Natural Resources, Beihai, China
| | - Wei Xu
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Linfeng Gong
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Rongchao He
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Weilu Qi
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Qiancheng Gao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Hongyan Cai
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Hans-Peter Grossart
- Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany.,Institute of Biochemistry and Biology, Postdam University, Potsdam, Germany
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
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Tangsricharoen T, Natesirinilkul R, Phusua A, Fanhchaksai K, Ittiwut C, Chetruengchai W, Juntharaniyom M, Charoenkwan P, Viprakasit V, Phokaew C, Shotelersuk V. Severe neonatal haemolytic anaemia caused by compound heterozygous KLF1 mutations: report of four families and literature review. Br J Haematol 2021; 194:626-634. [PMID: 34227100 DOI: 10.1111/bjh.17616] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/06/2021] [Accepted: 05/13/2021] [Indexed: 01/01/2023]
Abstract
Mutations in the KLF1 gene, which encodes a transcription factor playing a role in erythropoiesis, have recently been demonstrated to be a rare cause of hereditary haemolytic anaemia. We described the genotypic and phenotypic spectra of four unrelated families with compound heterozygous class 2/class 3 KLF1 mutations. All patients had p.G176RfsX179 on one allele and either p.A298P, p.R301H or p.G335R on the other allele. All presented on the first day of life with severe haemolytic anaemia with abnormal red blood cell morphology, markedly increased nucleated red blood cells and hyperbilirubinaemia. Three patients later became transfusion-dependent. All parents with heterozygous KLF1 mutation without co-inherited thalassaemia had normal to borderline mean corpuscular volume (MCV) and normal to slightly elevated Hb F. Fifteen previously reported cases of biallelic KLF1 mutations were identified from a literature review. All except one presented with severe haemolytic anaemia in the neonatal period. Our finding substantiates that compound heterozygous KLF1 mutations are associated with severe neonatal haemolytic anaemia and expands the haematologic phenotypic spectrum. In carriers, the previously suggested findings of low MCV, high Hb A2 and high Hb F are inconsistent; thus this necessitates molecular studies for the identification of carriers.
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Affiliation(s)
- Tanu Tangsricharoen
- Department of Pediatrics, Division of Hematology and Oncology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Rungrote Natesirinilkul
- Department of Pediatrics, Division of Hematology and Oncology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Arunee Phusua
- Department of Pediatrics, Division of Hematology and Oncology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kanda Fanhchaksai
- Department of Pediatrics, Division of Hematology and Oncology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Chupong Ittiwut
- Department of Pediatrics, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
| | - Wanna Chetruengchai
- Department of Pediatrics, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
| | - Monthana Juntharaniyom
- Department of Pediatrics, Division of Hematology and Oncology, Khon Kaen Regional Hospital, Khon Kaen, Thailand
| | - Pimlak Charoenkwan
- Department of Pediatrics, Division of Hematology and Oncology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Vip Viprakasit
- Department of Pediatrics, Division of Hematology and Oncology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chureerat Phokaew
- Department of Pediatrics, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
| | - Vorasuk Shotelersuk
- Department of Pediatrics, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
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Colaco S, Nadkarni A. Borderline HbA 2 levels: Dilemma in diagnosis of beta-thalassemia carriers. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2021; 788:108387. [PMID: 34893152 DOI: 10.1016/j.mrrev.2021.108387] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 05/27/2021] [Accepted: 06/08/2021] [Indexed: 12/17/2022]
Abstract
There is inconsistency in the exact definition of diagnostic levels of HbA2 for β thalassemia trait. While many laboratories consider HbA2 ≥4.0 % diagnostic, still others consider HbA2 ≥3.3 % or HbA2 ≥3.5 % as the cut-off for establishing β thalassemia carrier diagnosis. This is because, over the years, studies have described β thalassemia carriers showing HbA2 levels that lie above the normal range of HbA2 but below the typical carrier range of β thalassemia. These, "borderline HbA2 levels", though not detrimental to health, are significant in β thalassemia carrier diagnosis because they can lead to misinterpretation of results. In this review, we have evaluated the prevalence of borderline HbA2 levels and discussed the causes of borderline HbA2 values. We have also compiled an extensive catalogue of β globin gene defects associated with borderline HbA2 levels and have discussed strategies to avoid misdiagnosing borderline HbA2 β thalassemia carriers. Our analysis of studies that have delineated the cause of borderline HbA2 levels in different populations shows that 35.4 % [626/1766] of all individuals with borderline HbA2 levels carry a molecular defect. Among the positive samples, 17 % [299/1766] show β globin gene defects, 7.7 % [137/1766] show α thalassemia defects, 2.7 % [49/1766] show KLF1 gene mutations, 2.3 % [41/1766] show the co-inheritance of β and α thalassemia, 2.0 % [37/1766] show the co-inheritance of β and δ thalassemia and 1.8 % [32/1766] show α globin gene triplication. It appears that a comprehensive molecular work up of the β globin gene is the only definite method to detect borderline HbA2 β thalassemia carriers, especially in populations with a high prevalence of the disease. The presence of associated genetic or acquired determinants may subsequently be assessed to identify the cause of borderline HbA2.
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Affiliation(s)
- Stacy Colaco
- Department of Hematogenetics, ICMR-National Institute of Immunohematology, 13th Floor, K.E.M. Hospital Campus, Parel, Mumbai, 400 012, India
| | - Anita Nadkarni
- Department of Hematogenetics, ICMR-National Institute of Immunohematology, 13th Floor, K.E.M. Hospital Campus, Parel, Mumbai, 400 012, India.
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13
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Xu L, Zhu D, Zhang Y, Liang G, Liang M, Wei X, Feng X, Wu X, Shang X. Compound Heterozygosity for KLF1 Mutations Causing Hemolytic Anemia in Children: A Case Report and Literature Review. Front Genet 2021; 12:691461. [PMID: 34249106 PMCID: PMC8267787 DOI: 10.3389/fgene.2021.691461] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022] Open
Abstract
Background Anemia is one of the most common diseases affecting children worldwide. Hereditary forms of anemia due to gene mutations are difficult to diagnose because they only rely on clinical manifestations. In regions with high prevalence of thalassemia such as southern China, pediatric patients with a hereditary hemolytic anemia (HHA) phenotype are often diagnosed with β-thalassemia. However, HHA can be caused by other gene defects. Here, a case previously diagnosed with thalassemia in a local hospital was sent to our laboratory for further genetic diagnosis. Preliminary molecular testing did not identify any mutations in globin genes. Methods All blood samples were collected after informed consent had been obtain from the proband’s parents. Both clinical and genetic analyses were conducted for the patient and her family members, including clinical data collection and sequencing of the KLF1 gene. Relevant literature was reviewed, including genetically confirmed cases with well-documented clinical summaries. Results Based on the detailed clinical data for this case, we diagnosed the patient with severe HHA. Sanger sequencing confirmed that there was a mutation on each KLF1 allele in the proband, which is missense mutation c.892G > C (p.Ala298Pro) inherited from father and frameshift mutation c.525_526insCGGCGCC (p.Gly176Argfs∗179) from the mother, respectively. A summary of the KLF1 mutation spectrum and a clarification of genotype–phenotype correlation were performed through a combined analysis of the case and literature studies. Conclusion This study corrected the misdiagnosis and identified the etiology in a Chinese patient with HHA. Identification of the disease-causing gene is important for the treatment and care of the patient and prevention of another affected childbirth in her family. In addition, this study provided insight to better distinguish HHA patients with β-thalassemia mutations from those with KLF1 mutations.
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Affiliation(s)
- Linlin Xu
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Dina Zhu
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yanxia Zhang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Guanxia Liang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Min Liang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiaofeng Wei
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiaoqing Feng
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xuedong Wu
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xuan Shang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
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14
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Zakaria NA, Islam MA, Abdullah WZ, Bahar R, Mohamed Yusoff AA, Abdul Wahab R, Shamsuddin S, Johan MF. Epigenetic Insights and Potential Modifiers as Therapeutic Targets in β-Thalassemia. Biomolecules 2021; 11:755. [PMID: 34070036 PMCID: PMC8158146 DOI: 10.3390/biom11050755] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/01/2021] [Accepted: 05/12/2021] [Indexed: 01/28/2023] Open
Abstract
Thalassemia, an inherited quantitative globin disorder, consists of two types, α- and β-thalassemia. β-thalassemia is a heterogeneous disease that can be asymptomatic, mild, or even severe. Considerable research has focused on investigating its underlying etiology. These studies found that DNA hypomethylation in the β-globin gene cluster is significantly related to fetal hemoglobin (HbF) elevation. Histone modification reactivates γ-globin gene expression in adults and increases β-globin expression. Down-regulation of γ-globin suppressor genes, i.e., BCL11A, KLF1, HBG-XMN1, HBS1L-MYB, and SOX6, elevates the HbF level. β-thalassemia severity is predictable through FLT1, ARG2, NOS2A, and MAP3K5 gene expression. NOS2A and MAP3K5 may predict the β-thalassemia patient's response to hydroxyurea, a HbF-inducing drug. The transcription factors NRF2 and BACH1 work with antioxidant enzymes, i.e., PRDX1, PRDX2, TRX1, and SOD1, to protect erythrocytes from oxidative damage, thus increasing their lifespan. A single β-thalassemia-causing mutation can result in different phenotypes, and these are predictable by IGSF4 and LARP2 methylation as well as long non-coding RNA expression levels. Finally, the coinheritance of β-thalassemia with α-thalassemia ameliorates the β-thalassemia clinical presentation. In conclusion, the management of β-thalassemia is currently limited to genetic and epigenetic approaches, and numerous factors should be further explored in the future.
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Affiliation(s)
- Nur Atikah Zakaria
- Department of Haematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia; (N.A.Z.); (W.Z.A.); (R.B.)
| | - Md Asiful Islam
- Department of Haematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia; (N.A.Z.); (W.Z.A.); (R.B.)
| | - Wan Zaidah Abdullah
- Department of Haematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia; (N.A.Z.); (W.Z.A.); (R.B.)
| | - Rosnah Bahar
- Department of Haematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia; (N.A.Z.); (W.Z.A.); (R.B.)
| | - Abdul Aziz Mohamed Yusoff
- Department of Neurosciences, School of Medical Sciences, University Sains Malaysia, Kubang Kerian 16150, Malaysia;
| | - Ridhwan Abdul Wahab
- Department of Biomedical Sciences, Kulliyyah of Allied Health Sciences, International Islamic University Malaysia, Kuantan 25200, Malaysia;
| | - Shaharum Shamsuddin
- School of Health Sciences, University Sains Malaysia, Kubang Kerian 16150, Malaysia;
- Institute for Research in Molecular Medicine (INFORMM), University Sains Malaysia, Kubang Kerian 16150, Malaysia
- USM-RIKEN Interdisciplinary Collaboration for Advanced Sciences (URICAS), Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Muhammad Farid Johan
- Department of Haematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia; (N.A.Z.); (W.Z.A.); (R.B.)
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15
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Kumar R, Yadav R, Mishra S, Singh MPSS, Gwal A, Bharti PK, Rajasubramaniam S. Krüppel-like factor 1 (KLF1) gene single nucleotide polymorphisms in sickle cell disease and its association with disease-related morbidities. Ann Hematol 2021; 100:365-373. [PMID: 33388857 DOI: 10.1007/s00277-020-04381-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/16/2020] [Indexed: 10/22/2022]
Abstract
Sickle cell disease has varied clinical symptoms, and patients having high fetal hemoglobin (HbF) have milder symptoms. Various genetic factors are known to modulate the HbF levels. Krüppel-like factor 1 (KLF1) is a transcription factor that regulates the beta-like globin gene expression. Any variation in KLF1 gene may alter the sickle cell disease phenotype. Xmn-I polymorphism is also known to regulate the gamma globin gene expression. Present studies were carried out to investigate the effect of KLF1 gene mutations and Xmn-I polymorphism on the sickle cell disease severity and to ascertain the genotype-phenotype correlation. One hundred and eighteen sickle cell disease patients having a median follow-up of 5 years (3-10 years) were recruited. Clinical details were recorded from their retrospective medical records. Xmn-I polymorphism were analyzed using PCR-RFLP method. Variations in KLF1 gene were identified using Sanger sequencing. Out of 118 patients, 24 had acute chest syndrome and 21 patients had more than 2 pain episodes per year. There were no significant differences in sickle cell disease-related morbidities in male and females barring leg ulcers. A total of 6 polymorphism were observed in KLF1 gene, out of which 3 are novel (c.-304G > C, c.*141A > G and c.*178A > G). No statistically significant association of any of SNPs identified in KLF1 gene or Xmn-I polymorphism was seen with HbF levels as well as the sickle cell disease-related morbidities. No association exists between fetal hemoglobin or sickle cell disease-related morbidities and Xmn-I polymorphism or with SNPs identified in KLF1 gene in the studied cohort.
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Affiliation(s)
- Ravindra Kumar
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India
| | - Rajiv Yadav
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India
| | - Sweta Mishra
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India
| | - M P S S Singh
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India
| | - Anil Gwal
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India
| | - Praveen K Bharti
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India
| | - Shanmugam Rajasubramaniam
- ICMR-National Institute of Research in Tribal Health, Nagpur Road, P.O. Garha, Jabalpur, 482003, India.
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16
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Mehta P, Sawant P, Gorivale M, Nadkarni A, Colah R, Mukherjee MB. Prevalence of globin gene modifiers encountered in fetuses during antenatal diagnosis of hemoglobinopathies. Int J Lab Hematol 2020; 42:482-491. [PMID: 32412692 DOI: 10.1111/ijlh.13232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/19/2020] [Accepted: 04/17/2020] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The hemoglobinopathies are the commonest group of single gene disorders in the Indian subcontinent. Although genetic modifiers are known to have a remarkable effect on phenotypic expression, the effects of the possible co-inheritance of different modifiers are not taken into account during prenatal diagnosis. The present study was undertaken to look for the frequency of globin gene modifiers like the types of β-globin gene mutations, α thalassemia, α gene triplication, and the Xmn1 polymorphism in fetuses during antenatal diagnosis of hemoglobinopathies. MATERIALS AND METHODS A total of 580 fetuses with different diagnoses were screened for the presence of genetic modifiers. RESULTS Twenty-two different β-globin gene mutations were identified of which 3.5% were milder mutations. Among the affected fetuses, 29.6% of the β-thalassemia major and 52.9% of the sickle cell anemia (SCA) fetuses had one genetic modifier while 3.7% of the β-thalassemia major and 41.1% of the SCA fetuses had co-inherited two modifiers. α-gene triplication was detected in 16 (3.5%) β-thalassemia/sickle cell heterozygous and normal fetuses of which 5 babies (2 β-thalassemia heterozygous and 3 normal) could be followed up. Of the 2 β-thalassemia heterozygous babies, one had a severe clinical presentation. CONCLUSION Many fetuses had one or two gene modifiers. However, the impact of these on ameliorating the severity of the disease could not be evaluated as all the fetuses with β thalassemia major or sickle cell disease were terminated. Parents having heterozygous fetuses with α gene triplication should be followed up periodically after birth for better management of these babies.
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Affiliation(s)
- Pallavi Mehta
- ICMR-National Institute of Immunohaematology, Parel, India
| | | | - Manju Gorivale
- ICMR-National Institute of Immunohaematology, Parel, India
| | - Anita Nadkarni
- ICMR-National Institute of Immunohaematology, Parel, India
| | - Roshan Colah
- ICMR-National Institute of Immunohaematology, Parel, India
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17
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Nicolau M, Vargas S, Silva M, Coelho A, Ferreira E, Mendonça J, Vieira L, Kjöllerström P, Maia R, Silva R, Dias A, Ferreira T, Morais A, Soares IM, Lavinha J, Faustino P. Genetic modulators of fetal hemoglobin expression and ischemic stroke occurrence in African descendant children with sickle cell anemia. Ann Hematol 2019; 98:2673-2681. [PMID: 31478061 DOI: 10.1007/s00277-019-03783-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/11/2019] [Indexed: 02/06/2023]
Abstract
Sickle cell anemia (SCA) is an autosomal recessive monogenic disease with significant clinical variability. Cerebrovascular disease, particularly ischemic stroke, is one of the most severe complications of SCA in children. This study aimed to investigate the influence of genetic variants on the levels of fetal hemoglobin (Hb F) and biochemical parameters related with chronic hemolysis, as well as on ischemic stroke risk, in ninety-one unrelated SCA patients, children of sub-Saharan progenitors. Our results show that a higher Hb F level has an inverse relationship with the occurrence of stroke, since the group of patients who suffered stroke presents a significantly lower mean Hb F level (5.34 ± 4.57% versus 9.36 ± 6.48%; p = 0.024). Furthermore, the co-inheritance of alpha-thalassemia improves the chronic hemolytic pattern, evidenced by a decreased reticulocyte count (8.61 ± 3.58% versus 12.85 ± 4.71%; p < 0.001). In addition, our findings have confirmed the importance of HBG2 and BCL11A loci in the regulation of Hb F expression in sub-Saharan African SCA patients, as rs7482144_A, rs11886868_C, and rs4671393_A alleles are significantly associated with a considerable increase in Hb F levels (p = 0.019, p = 0.026, and p = 0.028, respectively). Concerning KLF1, twelve different variants were identified, two of them novel. Seventy-three patients (80.2%) presented at least one variant in this gene. However, no correlation was observed between the presence of these variants and Hb F level, severity of hemolysis, or stroke occurrence, which is consistent with their in silico-predicted minor functional consequences. Thus, we conclude that the prevalence of functional KLF1 variants in a sub-Saharan African background does not seem to be relevant to SCA clinical modulation.
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Affiliation(s)
- Marta Nicolau
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Sofia Vargas
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Marisa Silva
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Andreia Coelho
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Emanuel Ferreira
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Joana Mendonça
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Luís Vieira
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal.,ToxOmics, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Paula Kjöllerström
- Unidade de Hematologia, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central (CHULC), Lisbon, Portugal
| | - Raquel Maia
- Unidade de Hematologia, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central (CHULC), Lisbon, Portugal
| | - Rita Silva
- Unidade de Neuropediatria, Hospital de Dona Estefânia, CHULC, Lisbon, Portugal
| | - Alexandra Dias
- Núcleo de Hematologia, Departamento de Pediatria, Hospital Prof. Doutor Fernando Fonseca, Amadora, Portugal
| | - Teresa Ferreira
- Núcleo de Hematologia, Departamento de Pediatria, Hospital Prof. Doutor Fernando Fonseca, Amadora, Portugal
| | - Anabela Morais
- Departamento de Pediatria, Hospital de Santa Maria, Centro Hospitalar Universitário de Lisboa Norte, Lisbon, Portugal
| | | | - João Lavinha
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal.,BioISI, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Paula Faustino
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal. .,Instituto de Saúde Ambiental (ISAMB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal. .,Unidade de Investigação e Desenvolvimento, Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016, Lisbon, Portugal.
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