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Uehara E, Abe K, Tanase-Nakao K, Muroya K, Hattori A, Matsubara K, Fukami M, Narumi S. Molecular and Clinical Features of Congenital Hypothyroidism Due to Multiple DUOX2 Variants. Thyroid 2024; 34:827-836. [PMID: 38757580 DOI: 10.1089/thy.2024.0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Background: DUOX2 is one of the major causative genes of congenital hypothyroidism (CH). Still, the mutation spectrum and clinical outcomes of biallelic DUOX2 variants are not fully understood. This study aimed to elucidate the molecular features and long-term clinical manifestations of CH caused by multiple pathogenic DUOX2 variants. Methods: A total of 255 patients with CH were screened for rare variants of 11 known causative genes. DUOX2 variants were classified according to their protein structure and residual activity. In vitro assays were performed for several variants of unknown functions. Clinical analyses were conducted for patients with multiple pathogenic variants of DUOX2 but not of other genes. Results: We identified 24 pathogenic variants of DUOX2, together with two benign variants and seven variants of uncertain significance, in 63 patients. The pathogenic variants included three missense substitutions and one frameshift variant that have not yet been linked to CH. Twenty-one patients carried multiple pathogenic DUOX2 variants without any other pathogenic gene variants. Three of the 21 patients harbored homozygous variants. Family analysis, long-read amplicon sequencing, and haplotype phasing confirmed compound heterozygosity of the DUOX2 variants in 14 patients, whereas the allelic positions of the variants in the remaining four patients could not be determined. Of the 21 patients, 19 were treated with levothyroxine; their ages at drug withdrawal ranged from 9 months to 21.4 years. Three patients required retreatment after drug-free intervals of 6 months, 8 months, and 10 years. There were no differences in clinical severity among patients with DUOX2 amorphic/amorphic, amorphic/hypomorphic, and hypomorphic/hypomorphic variants. Conclusions: These results broaden the mutational spectrum of DUOX2. Furthermore, our data imply that patients with multiple pathogenic DUOX2 variants typically exhibit transient CH without significant genotype-phenotype correlations. Most importantly, this study demonstrated for the first time that these patients are at risk of developing recurrent hypothyroidism after a long drug-free interval.
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Affiliation(s)
- Erika Uehara
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Department of Advanced Pediatric Medicine, Tohoku University School of Medicine, Tokyo, Japan
| | - Kiyomi Abe
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
- Department of Pediatrics, Tokyo Saiseikai Central Hospital, Tokyo, Japan
| | - Kanako Tanase-Nakao
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Koji Muroya
- Department of Endocrinology and Metabolism, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Atsushi Hattori
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Division of Diversity Research, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Keiko Matsubara
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Division of Diversity Research, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Maki Fukami
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Division of Diversity Research, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Satoshi Narumi
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
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Liu HY, Huang J, Xiao H, Zhang MJ, Shi FF, Jiang YH, Du H, He Q, Wang ZY. Pseudodominant inheritance of autosomal recessive congenital stationary night blindness in one family with three co-segregating deleterious GRM6 variants identified by next-generation sequencing. Mol Genet Genomic Med 2019; 7:e952. [PMID: 31677249 PMCID: PMC6900388 DOI: 10.1002/mgg3.952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The congenital stationary night blindness (CSNB) affects the patients' dim light vision or dark adaption by impairing the normal function of retina. It is a clinically and genetically heterogeneous disorder and can be inherited in an X-linked, autosomal dominant or autosomal recessive pattern. Several genetic alterations to the genes involved in visual signal transduction of photoreceptors and/or bipolar cells underlie its pathogenesis. METHODS In this study, we used Sanger sequencing and next-generation sequencing (NGS)-based gene panel screening to investigate a family of three patients with CSNB inherited in an apparent autosomal dominant pattern. We expected to find out the disease-causing gene defects carried by this family. RESULTS We found that the patients in this family did not carry the RHO, GNAT1, or PDE6B mutation, but carried compound heterozygotes mutations of GRM6. Three deleterious GRM6 variants, p.Arg621Ter, p.Gly51Val, and p.Gly464Arg, were found to be co-segregating with the disease, causing a pseudodominant inheritance of GRM6-related autosomal recessive complete CSNB. CONCLUSION This study presents a rare case of autosomal recessive CSNB (arCSNB) pseudodominant inheritance, which potentially leads us to expand our gene candidate list in future genetic testing for apparent dominant pedigrees. The discovery of the two novel likely pathogenic variants p.Gly51Val and p.Gly464Arg could broaden our knowledge about the genetics of CSNB and provide insights into the structure and function of the GRM6 protein.
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Affiliation(s)
- Hong-Yan Liu
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
| | - Jia Huang
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
| | - Hai Xiao
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
| | - Ming-Jie Zhang
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
| | - Fei-Fei Shi
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
| | - Ying-Hai Jiang
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
| | - Han Du
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, China
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Abstract
Extracellular hydrogen peroxide is required for thyroperoxidase-mediated thyroid hormone synthesis in the follicular lumen of the thyroid gland. Among the NADPH oxidases, dual oxidases, DUOX1 and DUOX2, constitute a distinct subfamily initially identified as thyroid oxidases, based on their level of expression in the thyroid. Despite their high sequence similarity, the two isoforms present distinct regulations, tissue expression, and catalytic functions. Inactivating mutations in many of the genes involved in thyroid hormone synthesis cause thyroid dyshormonogenesis associated with iodide organification defect. This chapter provides an overview of the genetic alterations in DUOX2 and its maturation factor, DUOXA2, causing inherited severe hypothyroidism that clearly demonstrate the physiological implication of this oxidase in thyroid hormonogenesis. Mutations in the DUOX2 gene have been described in permanent but also in transient forms of congenital hypothyroidism. Moreover, accumulating evidence demonstrates that the high phenotypic variability associated with altered DUOX2 function is not directly related to the number of inactivated DUOX2 alleles, suggesting the existence of other pathophysiological factors. The presence of two DUOX isoforms and their corresponding maturation factors in the same organ could certainly constitute an efficient redundant mechanism to maintain sufficient H2O2 supply for iodide organification. Many of the reported DUOX2 missense variants have not been functionally characterized, their clinical impact in the observed phenotype remaining unresolved, especially in mild transient congenital hypothyroidism. DUOX2 function should be carefully evaluated using an in vitro assay wherein (1) DUOXA2 is co-expressed, (2) H2O2 production is activated, (3) and DUOX2 membrane expression is precisely analyzed.
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Affiliation(s)
- Xavier De Deken
- Faculté de Médecine, Université Libre de Bruxelles (ULB), Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Brussels, Belgium.
| | - Françoise Miot
- Faculté de Médecine, Université Libre de Bruxelles (ULB), Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Brussels, Belgium
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Sun F, Zhang JX, Yang CY, Gao GQ, Zhu WB, Han B, Zhang LL, Wan YY, Ye XP, Ma YR, Zhang MM, Yang L, Zhang QY, Liu W, Guo CC, Chen G, Zhao SX, Song KY, Song HD. The genetic characteristics of congenital hypothyroidism in China by comprehensive screening of 21 candidate genes. Eur J Endocrinol 2018; 178:623-633. [PMID: 29650690 PMCID: PMC5958289 DOI: 10.1530/eje-17-1017] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 04/11/2018] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Congenital hypothyroidism (CH), the most common neonatal metabolic disorder, is characterized by impaired neurodevelopment. Although several candidate genes have been associated with CH, comprehensive screening of causative genes has been limited. DESIGN AND METHODS One hundred ten patients with primary CH were recruited in this study. All exons and exon-intron boundaries of 21 candidate genes for CH were analyzed by next-generation sequencing. And the inheritance pattern of causative genes was analyzed by the study of family pedigrees. RESULTS Our results showed that 57 patients (51.82%) carried biallelic mutations (containing compound heterozygous mutations and homozygous mutations) in six genes (DUOX2, DUOXA2, DUOXA1, TG, TPO and TSHR) involved in thyroid hormone synthesis. Autosomal recessive inheritance of CH caused by mutations in DUOX2, DUOXA2, TG and TPO was confirmed by analysis of 22 family pedigrees. Notably, eight mutations in four genes (FOXE1, NKX2-1, PAX8 and HHEX) that lead to thyroid dysgenesis were identified in eight probands. These mutations were heterozygous in all cases and hypothyroidism was not observed in parents of these probands. CONCLUSIONS Most cases of congenital hypothyroidism in China were caused by thyroid dyshormonogenesis rather than thyroid dysgenesis. This study identified previously reported causative genes for 57/110 Chinese patients and revealed DUOX2 was the most frequently mutated gene in these patients. Our study expanded the mutation spectrum of CH in Chinese patients, which was significantly different from Western countries.
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Affiliation(s)
- Feng Sun
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jun-Xiu Zhang
- Department of EndocrinologyMaternal and Child Health Institute of Bozhou, Bozhou, China
| | - Chang-Yi Yang
- Department of EndocrinologyFujian Province Maternity & Children Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
| | - Guan-Qi Gao
- Department of EndocrinologyThe Linyi People’s Hospital, Linyi, Shandong Province, China
| | - Wen-Bin Zhu
- Department of EndocrinologyFujian Province Maternity & Children Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
| | - Bing Han
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Le-Le Zhang
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yue-Yue Wan
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiao-Ping Ye
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu-Ru Ma
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Man-Man Zhang
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Liu Yang
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Qian-Yue Zhang
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wei Liu
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Cui-Cui Guo
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Gang Chen
- Department of EndocrinologyFujian Province Hospital, Fuzhou, Fujian Province, China
| | - Shuang-Xia Zhao
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ke-Yi Song
- Department of EndocrinologyThe People’s Hospital of Bozhou, Bozhou, Anhui Province, China
| | - Huai-Dong Song
- The Core Laboratory in Medical Center of Clinical ResearchDepartment of Endocrinology, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Correspondence should be addressed to H-D Song;
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Abstract
After the identification of thyroid H2O2 generation system (DUOX) and of its maturation factors (DUOXA), defects in DUOX2 and/or DUOXA2 were rapidly recognized as the possible cause of congenital hypothyroidism (CH) due to thyroid dyshormonogenesis. The present Review reports data on the prevalence of DUOX2 mutations, which is variable among different series but invariably high, pointing to DUOX2 defects as one of the leading causes of dyshormonogenesis. Differently, DUOXA defects seem to be rarely involved in the pathogenesis of CH. Genotype-phenotype correlations are also reported, highlighting the great intra- and inter-familial phenotype variability which appears to be a constant feature of the defects in the H2O2 generation systems. Finally, the hypotheses to explain the phenotypic variability of the DUOX2/A2 mutations are discussed, such as the existence of other H2O2 generating systems, the age variability in thyroid hormones requirements, the differences in ethnicity, in iodine intake, and in the methodological approaches.
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Affiliation(s)
- Marina Muzza
- Endocrine Unit, Fondazione IRCCS Ca' Granda Policlinico, Milan, Italy
| | - Laura Fugazzola
- Division of Endocrine and Metabolic Diseases, IRCCS Istituto Auxologico Italiano, Dept. of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
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High prevalence of DUOX2 gene mutations among children with congenital hypothyroidism in central China. Eur J Med Genet 2016; 59:526-31. [PMID: 27498126 DOI: 10.1016/j.ejmg.2016.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 07/22/2016] [Indexed: 11/20/2022]
Abstract
Congenial hypothyroidism (CH) is the most common congenital endocrine disease and is treatable when recognized early enough. We investigated the genetic variants in 12 children diagnosed with CH by newborn screening in Huangshi area central China. Twelve genes commonly involved in CH development were studied. Genomic DNA from peripheral blood was used to amplify all exons of the selected genes, and the constructed sequencing libraries were subjected to next generation high throughput DNA sequencing (NGS). Analysis of the sequencing results identified rare genetic variants in 11 of the 12 patients (91.7%), and two novel rare variants were found in DUOX2 gene and two in TPO gene. Mutations in DUOX2 gene were identified in 10 patients (83.3%), and all these patients were found to carry bi-allelic, tri-allelic mutations or compound mutations with other genes. Recurrent DUOX2 mutations include K530X, R683L, R1110Q, and L1343F. Truncating, splicing, and proven deleterious DUOX2 missense mutations were detected in 50% of the patients. Mutations in TG gene were identified in four patients, and mutations in TPO, THSR, SLC26A4 genes were identified, one in each patient, respectively. The high prevalence of DUOX2 mutations in this cohort of children with CH appears striking and surprising. The clinical implications were discussed.
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Matsuo K, Tanahashi Y, Mukai T, Suzuki S, Tajima T, Azuma H, Fujieda K. High prevalence of DUOX2 mutations in Japanese patients with permanent congenital hypothyroidism or transient hypothyroidism. J Pediatr Endocrinol Metab 2016; 29:807-12. [PMID: 27166716 DOI: 10.1515/jpem-2015-0400] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/29/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Dual oxidase 2 (DUOX2) mutations are a cause of dyshormonogenesis (DH) and have been identified in patients with permanent congenital hypothyroidism (PH) and with transient hypothyroidism (TH). We aimed to elucidate the prevalence and phenotypical variations of DUOX2 mutations. METHODS Forty-eight Japanese DH patients were enroled and analysed for sequence variants of DUOX2, DUOXA2, and TPO using polymerase chain reaction-amplified direct sequencing. RESULTS Fourteen sequence variants of DUOX2, including 10 novel variants, were identified in 11 patients. DUOX2 variants were more prevalent (11/48, 22.9%) than TPO (3/48, 6.3%) (p=0.020). The prevalence of DUOX2 variants in TH was slightly, but not significantly, higher than in PH. Furthermore, one patient had digenic heterozygous sequence variants of both DUOX2 and TPO. CONCLUSIONS Our results suggest that DUOX2 mutations might be the most common cause of both PH and TH, and that phenotypes of these mutations might be milder than those of other causes.
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Maruo Y, Nagasaki K, Matsui K, Mimura Y, Mori A, Fukami M, Takeuchi Y. Natural course of congenital hypothyroidism by dual oxidase 2 mutations from the neonatal period through puberty. Eur J Endocrinol 2016; 174:453-63. [PMID: 26742565 DOI: 10.1530/eje-15-0959] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 01/07/2016] [Indexed: 11/08/2022]
Abstract
AIM We previously reported that biallelic mutations in dual oxidase 2 (DUOX2) cause transient hypothyroidism. Since then, many cases with DUOX2 mutations have been reported. However, the clinical features and prognosis of individuals with DUOX2 defects have not been clarified. OBJECTIVE We investigated the prognosis of patients with congenital hypothyroidism (CH) due to DUOX2 mutations. PATIENTS Twenty-five patients were identified by a neonatal screening program and included seven familial cases. Their serum TSH values ranged from 18.9 to 734.6 mU/l. Twenty-two of the patients had low serum free thyroxine (fT4) levels (0.17-1.1 ng/dl). Twenty-four of the patients were treated with L-thyroxine. METHODS We analyzed the DUOX2, thyroid peroxidase, Na(+)/I(-) symporter, and dual oxidase maturation factor 2 genes of these 25 patients by PCR-amplified direct sequencing. An additional 11 genes were analyzed in 11 of the 25 patients using next-generation sequencing. RESULTS All patients had biallelic DUOX2 mutations, and seven novel alleles were detected. Fourteen of the patients were able to discontinue replacement therapy, and seven were receiving reduced L-thyroxine doses. Normalization of thyroglobulin lagged several years behind the completion of treatment. Two patients showed permanent hypothyroidism. Except for one case of a learning disability, growth and psychomotor development were normal. CONCLUSION The prognosis of Japanese patients with DUOX2 defects was usually transient CH. Delayed improvement of thyroglobulin indicates that these patients have subclinical hypothyroidism. Hypothyroidism did not recur in patients during the study period (up to 18 years old).
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Affiliation(s)
- Yoshihiro Maruo
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
| | - Keisuke Nagasaki
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
| | - Katsuyuki Matsui
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
| | - Yu Mimura
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
| | - Asami Mori
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
| | - Maki Fukami
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
| | - Yoshihiro Takeuchi
- Department of PediatricsShiga University of Medical Science, Tsukinowa, Seta, Otsu, Shiga 520-2192, JapanDepartment of PediatricsNiigata University, Niigata, JapanDepartment of Molecular EndocrinologyNational Research Institute for Child Health and Development, Tokyo, Japan
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Belforte FS, Citterio CE, Testa G, Olcese MC, Sobrero G, Miras MB, Targovnik HM, Rivolta CM. Compound heterozygous DUOX2 gene mutations (c.2335-1G>C/c.3264_3267delCAGC) associated with congenital hypothyroidism. Characterization of complex cryptic splice sites by minigene analysis. Mol Cell Endocrinol 2016; 419:172-84. [PMID: 26506010 DOI: 10.1016/j.mce.2015.10.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 09/25/2015] [Accepted: 10/19/2015] [Indexed: 12/11/2022]
Abstract
Iodide Organification defects (IOD) represent 10% of cases of congenital hypothyroidism (CH) being the main genes affected that of TPO (thyroid peroxidase) and DUOX2 (dual oxidasa 2). From a patient with clinical and biochemical criteria suggestive with CH associated with IOD, TPO and DUOX2 genes were analyzed by means of PCR-Single Strand Conformation Polymorphism analysis and sequencing. A novel heterozygous compound to the mutations c.2335-1G>C (paternal mutation, intron 17) and c.3264_3267delCAGC (maternal mutation, exon 24) was identified in the DUOX2 gene. Ex-vivo splicing assays and subsequent RT-PCR and sequencing analyses were performed on mRNA isolated from the HeLa cells transfected with wild-type and mutant pSPL3 expression vectors. The wild-type and c.2335-1G>C mutant alleles result in the complete inclusion or exclusion of exon 18, or in the activation of an exonic cryptic 5' ss with the consequent deletion of 169 bp at the end of this exon. However, we observed only a band of the expected size in normal thyroid tissue by RT-PCR. Additionally, the c.2335-1G>C mutation activates an unusual cryptic donor splice site in intron 17, located at position -14 of the authentic intron 17/exon 18 junction site, with an insertion of the last 14 nucleotides of the intron 17 in mutant transcripts with complete and partial inclusion of exon 18. The theoretical consequences of splice site mutation, predicted with the bioinformatics NNSplice, Fsplice, SPL, SPLM and MaxEntScan programs were investigated and evaluated in relation with the experimental evidence. These analyses confirm that c.2335-1G>C mutant allele would result in the abolition of the authentic splice acceptor site. The results suggest the coexistence in our patient of four putative truncated proteins of 786, 805, 806 and 1105 amino acids, with conservation of peroxidase-like domain and loss of gp91(phox)/NOX2-like domain. In conclusion a novel heterozygous compound was identified being responsible of IOD. Cryptic splicing sites have been characterized in DUOX2 gene for the first time. The use of molecular biology techniques is a valuable tool for understanding the molecular pathophysiology of this type of thyroid defects.
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Affiliation(s)
- Fiorella S Belforte
- Laboratorio de Genética Molecular Tiroidea, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Cintia E Citterio
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Graciela Testa
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, 5000 Córdoba, Argentina
| | - María Cecilia Olcese
- Laboratorio de Genética Molecular Tiroidea, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Gabriela Sobrero
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, 5000 Córdoba, Argentina
| | - Mirta B Miras
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, 5000 Córdoba, Argentina
| | - Héctor M Targovnik
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Carina M Rivolta
- Laboratorio de Genética Molecular Tiroidea, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética (FFyB-UBA), C1113AAD Buenos Aires, Argentina.
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O'Neill S, Brault J, Stasia MJ, Knaus UG. Genetic disorders coupled to ROS deficiency. Redox Biol 2015; 6:135-156. [PMID: 26210446 PMCID: PMC4550764 DOI: 10.1016/j.redox.2015.07.009] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/15/2015] [Accepted: 07/16/2015] [Indexed: 12/24/2022] Open
Abstract
Maintaining the redox balance between generation and elimination of reactive oxygen species (ROS) is critical for health. Disturbances such as continuously elevated ROS levels will result in oxidative stress and development of disease, but likewise, insufficient ROS production will be detrimental to health. Reduced or even complete loss of ROS generation originates mainly from inactivating variants in genes encoding for NADPH oxidase complexes. In particular, deficiency in phagocyte Nox2 oxidase function due to genetic variants (CYBB, CYBA, NCF1, NCF2, NCF4) has been recognized as a direct cause of chronic granulomatous disease (CGD), an inherited immune disorder. More recently, additional diseases have been linked to functionally altered variants in genes encoding for other NADPH oxidases, such as for DUOX2/DUOXA2 in congenital hypothyroidism, or for the Nox2 complex, NOX1 and DUOX2 as risk factors for inflammatory bowel disease. A comprehensive overview of novel developments in terms of Nox/Duox-deficiency disorders is presented, combined with insights gained from structure-function studies that will aid in predicting functional defects of clinical variants.
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Affiliation(s)
- Sharon O'Neill
- Conway Institute, University College Dublin, Dublin, Ireland
| | - Julie Brault
- Université Grenoble Alpes, TIMC-IMAG Pôle Biologie, CHU de Grenoble, Grenoble, France; CGD Diagnosis and Research Centre, Pôle Biologie, CHU de Grenoble, Grenoble, France
| | - Marie-Jose Stasia
- Université Grenoble Alpes, TIMC-IMAG Pôle Biologie, CHU de Grenoble, Grenoble, France; CGD Diagnosis and Research Centre, Pôle Biologie, CHU de Grenoble, Grenoble, France
| | - Ulla G Knaus
- Conway Institute, University College Dublin, Dublin, Ireland.
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Fu C, Zhang S, Su J, Luo S, Zheng H, Wang J, Qin H, Chen Y, Shen Y, Hu X, Fan X, Luo J, Xie B, Chen R, Chen S. Mutation screening of DUOX2 in Chinese patients with congenital hypothyroidism. J Endocrinol Invest 2015; 38:1219-24. [PMID: 26349762 DOI: 10.1007/s40618-015-0382-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/12/2015] [Indexed: 11/25/2022]
Abstract
BACKGROUND Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder in infancy. Dual oxidase 2 gene (DUOX2) mutations have been reported to be one of the leading genetic causes of CH. AIM The aim of this study was to screen for DUOX2 gene mutations among CH patients in the Guangxi Zhuang Autonomous Region of China and to define the relationships between DUOX2 genotypes and clinical phenotypes. MATERIALS AND METHODS Blood samples were collected from 45 CH patients in Guangxi Zhuang Autonomous Region, China, and genomic DNA was extracted from peripheral blood leukocytes. All exons of the DUOX2 gene together with their exon-intron boundaries were screened by Sanger sequencing. RESULTS Sequencing analysis of DUOX2 in 45 CH patients revealed ten different variants in thirteen individuals. The variants included five known mutations, namely c.3329G>A (p.R1110Q), c.1588A>T (p.K530X), c.2635G>A (p.E879K), c.2524C>T (p.R842X) and c.4027G>T (p.L1343F), and one novel frame shift variant c.3340delC (p.L1114SfsX56), as well as four novel missense variants c.903G>T (p.W301C), c.2048G>T (p.R683L), c.1736T>C (p.L579P) and c.3413C>A (p.A1138D). The variant p.K530X is highly recurrent in our patient cohort but the clinical phenotypes vary greatly among those carrying this variant. Most patients with monoallelic or biallelic DUOX2 pathogenic variants turned out to be cases of transient congenital hypothyroidism (TCH), while three patients with triallelic DUOX2 pathogenic variants were associated with permanent congenital hypothyroidism (PCH). CONCLUSIONS The prevalence of DUOX2 pathogenic variants was high (29 %) among patients with CH in Guangxi, China. Monoallelic and biallelic DUOX2 pathogenic variants were mainly associated with TCH, while triallelic DUOX2 pathogenic variants were associated with PCH. Our study expanded the DUOX2 mutation spectrum, and functional studies of the novel mutations need to be conducted in the future.
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Affiliation(s)
- C Fu
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - S Zhang
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - J Su
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - S Luo
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - H Zheng
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - J Wang
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - H Qin
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - Y Chen
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - Y Shen
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA, 02115, USA
| | - X Hu
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - X Fan
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - J Luo
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - B Xie
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - R Chen
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China
| | - S Chen
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, People's Republic of China.
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