1
|
Yamaguchi N, Suzuki A, Yoshida A, Tanaka T, Aoyama K, Oishi H, Hara Y, Ogi T, Amano I, Kameo S, Koibuchi N, Shibata Y, Ugawa S, Mizuno H, Saitoh S. The iodide transporter Slc26a7 impacts thyroid function more strongly than Slc26a4 in mice. Sci Rep 2022; 12:11259. [PMID: 35788623 PMCID: PMC9253019 DOI: 10.1038/s41598-022-15151-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 06/20/2022] [Indexed: 11/09/2022] Open
Abstract
SLC26A4 is a known iodide transporter, and is localized at the apical membrane of thyrocytes. Previously, we reported that SLC26A7 is also involved in iodide transport and that Slc26a7 is a novel causative gene for congenital hypothyroidism. However, its detailed role in vivo remains to be elucidated. We generated mice that were deficient in Slc26a7 and Slc26a4 to delineate differences and associations in their roles in iodide transport. Slc26a7-/- mice showed goitrous congenital hypothyroidism and mild growth failure on a normal diet. Slc26a7-/- mice with a low iodine environment showed marked growth failure. In contrast, Slc26a4-/- mice showed no growth failure and hypothyroidism in the same low iodine environment. Double-deficient mice showed more severe growth failure than Slc26a7-/- mice. RNA-seq analysis revealed that the number of differentially expressed genes (DEGs) in Slc26a7-/- mice was significantly higher than that in Slc26a4-/- mice. These indicate that SLC26A7 is more strongly involved in iodide transport and the maintenance of thyroid function than SLC26A4.
Collapse
Affiliation(s)
- Naoya Yamaguchi
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
| | - Atsushi Suzuki
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
| | - Aya Yoshida
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
| | - Tatsushi Tanaka
- Department of Pediatrics, Toyohashi Municipal Hospital, Toyohashi, Japan
| | - Kohei Aoyama
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan.
| | - Hisashi Oishi
- Department of Comparative and Experimental Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yuichiro Hara
- Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Department of Human Genetics and Molecular Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomoo Ogi
- Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Department of Human Genetics and Molecular Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Izuki Amano
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Satomi Kameo
- Department of Nutrition, Koshien University, Takarazuka, Japan
| | - Noriyuki Koibuchi
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yasuhiro Shibata
- Department of Anatomy and Neuroscience, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Shinya Ugawa
- Department of Anatomy and Neuroscience, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Haruo Mizuno
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
| |
Collapse
|
2
|
Ishii J, Suzuki A, Kimura T, Tateyama M, Tanaka T, Yazawa T, Arimasu Y, Chen IS, Aoyama K, Kubo Y, Saitoh S, Mizuno H, Kamma H. Congenital goitrous hypothyroidism is caused by dysfunction of the iodide transporter SLC26A7. Commun Biol 2019; 2:270. [PMID: 31372509 PMCID: PMC6656751 DOI: 10.1038/s42003-019-0503-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 06/13/2019] [Indexed: 12/27/2022] Open
Abstract
Iodide transport and storage in the thyroid follicles is crucial for thyroid hormone synthesis. Pendrin, the iodide exporter that transports iodide to thyroid follicles, is responsible for Pendred syndrome, a disorder characterized by congenital hypothyroidism and hearing loss. However, thyroid hormone levels are basically normal in patients with Pendred syndrome, indicating the presence of another unknown iodide transporter. Here, we show that SLC26A7 is a novel iodide transporter in the thyroid. We observe that SLC26A7 is specifically expressed in normal thyroid tissues and demonstrate its function in iodide transport. Using whole-exome sequencing, we also find a homozygous nonsense mutation in SLC26A7 (c.1498 C > T; p.Gln500Ter) in two siblings with congenital goitrous hypothyroidism. The mutated SLC26A7 protein shows an abnormal cytoplasmic localisation and lacks the iodide transport function. These results reveal that SLC26A7 functions as a novel iodide transporter in the thyroid and its dysfunction affects thyroid hormonogenesis in humans and causes congenital goitrous hypothyroidism.
Collapse
Affiliation(s)
- Jun Ishii
- Department of Pathology, Kyorin University School of Medicine, Tokyo, Japan
- Department of Pathology, Dokkyo Medical University, Tochigi, Japan
| | - Atsushi Suzuki
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Michihiro Tateyama
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Tatsushi Tanaka
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takuya Yazawa
- Department of Pathology, Dokkyo Medical University, Tochigi, Japan
| | - Yu Arimasu
- Department of Pathology, Kyorin University School of Medicine, Tokyo, Japan
| | - I-Shan Chen
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Kohei Aoyama
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yoshihiro Kubo
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Haruo Mizuno
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
- Department of Pediatrics, International University of Health and Welfare, School of Medicine, Narita, Japan
| | - Hiroshi Kamma
- Department of Pathology, Kyorin University School of Medicine, Tokyo, Japan
| |
Collapse
|
3
|
Du Y, Huang L, Wang X, Cui Q, Cheng X, Zhao L, Ni T. Clinical data analysis of genotypes and phenotypes of deafness gene mutations in newborns: A retrospective study. Biosci Trends 2017; 11:460-468. [PMID: 28717060 DOI: 10.5582/bst.2017.01070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We retrospectively analyzed newborns with deafness gene mutations and summarized the relationship between genotype and phenotype to provide a basis for genetic counseling. We studied 582 subjects positive for deafness gene mutations that were treated in the otology outpatient department of Beijing Tongren Hospital, Capital Medical University, between April 2012 and April 2016. The subjects were divided into 3 categories: a diagnosed group (group A), which was further subdivided into subgroups A1 (homozygous and compound heterozygous GJB2 mutations) and A2 (homozygous and compound heterozygous SLC26A4 mutations); a drug-induced deafness group (group B, mitochondrial (Mt) gene mutations); and a mutation carrier group (group C), which was further subdivided into the subgroups C1 (GJB2 heterozygous mutations), C2 (SLC26A4 heterozygous mutations), C3 (GJB3 heterozygous mutations), and C4 (double gene mutations). Partial sequences positive for GJB2 or SLC26A4 were sequenced and analyzed for mutations. Subjects underwent otoscopic examination and comprehensive audiological evaluation, and temporal bone computerized tomography and/or inner ear magnetic resonance imaging were performed. GJB2 235delC was the most common mutation locus. The highest proportion of deafness detected during universal newborn hearing screening was for drug-induced deafness, whereas the lowest was for the diagnosed group. GJB2 gene mutations mainly resulted in flat-type, profound-to-severe sensorineural hearing loss (SNHL). SLC26A4 gene mutation was mainly associated with high-frequency drop-type and profound-severe SNHL and was closely related to enlargement of the vestibular aqueduct.
Collapse
Affiliation(s)
- Yating Du
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education
| | - Lihui Huang
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education
| | - Xueyao Wang
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education
| | - Qingjia Cui
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education.,Beijing Rehabilitation Hospital, Capital Medical University; Rehabilitation Centre of Otolaryngology Head and Neck Surgery
| | - Xiaohua Cheng
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education
| | - Liping Zhao
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education
| | - Tingting Ni
- Beijing Tongren Hospital, Capital Medical University; Beijing Institute of Otolaryngology; Key Laboratory of Otolaryngology, Head and Neck Surgery, Ministry of Education
| |
Collapse
|
4
|
Abstract
Pendred syndrome is an autosomal recessive disorder that is classically defined by the combination of sensorineural deafness/hearing impairment, goiter, and an abnormal organification of iodide with or without hypothyroidism. The hallmark of the syndrome is the impaired hearing, which is associated with inner ear malformations such as an enlarged vestibular aqueduct (EVA). The thyroid phenotype is variable and may be modified by the nutritional iodine intake. Pendred syndrome is caused by biallelic mutations in the SLC26A4/PDS gene, which encodes the multifunctional anion exchanger pendrin. Pendrin has affinity for chloride, iodide, and bicarbonate, among other anions. In the inner ear, pendrin functions as a chloride/bicarbonate exchanger that is essential for maintaining the composition and the potential of the endolymph. In the thyroid, pendrin is expressed at the apical membrane of thyroid cells facing the follicular lumen. Functional studies have demonstrated that pendrin can mediate iodide efflux in heterologous cells. This, together with the thyroid phenotype observed in humans (goiter, impaired iodine organification) suggests that pendrin could be involved in iodide efflux into the lumen, one of the steps required for thyroid hormone synthesis. Iodide efflux can, however, also occur in the absence of pendrin suggesting that other exchangers or channels are involved. It has been suggested that Anoctamin 1 (ANO1/TMEM16A), a calcium-activated anion channel, which is also expressed at the apical membrane of thyrocytes, could participate in mediating apical efflux. In the kidney, pendrin is involved in bicarbonate secretion and chloride reabsorption. While there is no renal phenotype under basal conditions, severe metabolic alkalosis has been reported in Pendred syndrome patients exposed to an increased alkali load. This review provides an overview on the clinical spectrum of Pendred syndrome, the functional data on pendrin with a focus on its potential role in the thyroid, as well as the controversy surrounding the relative physiological roles of pendrin and anoctamin.
Collapse
Affiliation(s)
- Jean-Louis Wémeau
- Université de Lille 2, Centre Hospitalier Régional Universitaire de Lille, Clinique Endocrinologique Marc-Linquette, 59037 Lille, France.
| | - Peter Kopp
- Northwestern University, Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Tarry 15, 303 East Chicago Avenue, Chicago, IL 60611, USA.
| |
Collapse
|
5
|
Abstract
Breast cancer is the second most common cancer worldwide and the leading cause of cancer death in women, with incidence rates that continue to rise. The heterogeneity of the disease makes breast cancer exceptionally difficult to treat, particularly for those patients with triple-negative disease. To address the therapeutic complexity of these tumours, new strategies for diagnosis and treatment are urgently required. The ability of lactating and malignant breast cells to uptake and transport iodide has led to the hypothesis that radioiodide therapy could be a potentially viable treatment for many breast cancer patients. Understanding how iodide is transported, and the factors regulating the expression and function of the proteins responsible for iodide transport, is critical for translating this hypothesis into reality. This review covers the three known iodide transporters - the sodium iodide symporter, pendrin and the sodium-coupled monocarboxylate transporter - and their role in iodide transport in breast cells, along with efforts to manipulate them to increase the potential for radioiodide therapy as a treatment for breast cancer.
Collapse
Affiliation(s)
- Vikki L Poole
- School of Clinical and Experimental MedicineInstitute of Biomedical Research, University of Birmingham, Birmingham B15 2TT, UK
| | - Christopher J McCabe
- School of Clinical and Experimental MedicineInstitute of Biomedical Research, University of Birmingham, Birmingham B15 2TT, UK
| |
Collapse
|
6
|
Silveira JC, Kopp PA. Pendrin and anoctamin as mediators of apical iodide efflux in thyroid cells. Curr Opin Endocrinol Diabetes Obes 2015; 22:374-80. [PMID: 26313899 DOI: 10.1097/med.0000000000000188] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW Thyroid hormones are essential for normal development, growth, and metabolism. Their synthesis occurs in thyroid follicles and requires an adequate iodide supply and a sequence of regulated biochemical steps. The uptake of iodide into thyrocytes is well characterized, but its efflux at the apical membrane is poorly understood. This review discusses potential mechanisms underlying iodide efflux with emphasis on recent developments and controversies. RECENT FINDINGS The functional characterization of pendrin (PDS/SLC26A4), a multifunctional anion exchanger, suggested that it could be involved in mediating iodide efflux. This is supported by the phenotype of patients with Pendred syndrome (deafness, goiter, partial iodide organification defect), which is caused by biallelic mutations in the SLC26A4 gene, as well as functional studies. However, apical iodide efflux is also possible in the absence of pendrin, implicating the presence of at least another channel. Recently, Anoctamin 1 (TMEM16A), a calcium-activated anion channel has been identified at the apical membrane of thyrocytes and functional studies suggest that it may play a predominant role in mediating iodide efflux. SUMMARY Anoctamin and pendrin are two plausible candidates as mediators of apical iodide efflux. Their relative affinity for iodide and their exact physiological role await, however, further characterization.
Collapse
Affiliation(s)
- Jamile C Silveira
- aDivision of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA bDepartment of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | |
Collapse
|
7
|
Atrophic thyroid follicles and inner ear defects reminiscent of cochlear hypothyroidism in Slc26a4-related deafness. Mamm Genome 2014; 25:304-16. [PMID: 24760582 DOI: 10.1007/s00335-014-9515-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 04/03/2014] [Indexed: 01/10/2023]
Abstract
Thyroid hormone is essential for inner ear development and is required for auditory system maturation. Human mutations in SLC26A4 lead to a syndromic form of deafness with enlargement of the thyroid gland (Pendred syndrome) and non-syndromic deafness (DFNB4). We describe mice with an Slc26a4 mutation, Slc26a4 (loop/loop) , which are profoundly deaf but show a normal sized thyroid gland, mimicking non-syndromic clinical signs. Histological analysis of the thyroid gland revealed defective morphology, with a majority of atrophic microfollicles, while measurable thyroid hormone in blood serum was within the normal range. Characterization of the inner ear showed a spectrum of morphological and molecular defects consistent with inner ear pathology, as seen in hypothyroidism or disrupted thyroid hormone action. The pathological inner ear hallmarks included thicker tectorial membrane with reduced β-tectorin protein expression, the absence of BK channel expression of inner hair cells, and reduced inner ear bone calcification. Our study demonstrates that deafness in Slc26a4 (loop/loop) mice correlates with thyroid pathology, postulating that sub-clinical thyroid morphological defects may be present in some DFNB4 individuals with a normal sized thyroid gland. We propose that insufficient availability of thyroid hormone during inner ear development plays an important role in the mechanism underlying deafness as a result of SLC26A4 mutations.
Collapse
|
8
|
Huang CJ, Lei TH, Chang WL, Tu TY, Shiao AS, Chiu CY, Jap TS. A Novel mutation in the SLC26A4 gene in a Chinese family with Pendred syndrome. Int J Pediatr Otorhinolaryngol 2013; 77:1495-9. [PMID: 23838540 DOI: 10.1016/j.ijporl.2013.06.017] [Citation(s) in RCA: 5] [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: 04/16/2013] [Revised: 06/15/2013] [Accepted: 06/18/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To investigate the mutations in the SLC26A4 gene in a Chinese patient with Pendred syndrome. METHODS The diagnosis of Pendred syndrome was confirmed by the family history, pure tone audiogram, perchlorate discharge test (PDT), and computed tomography (CT) of the temporal bone. DNA extraction, PCR and DNA sequencing were performed according to standard procedures. Mutations in the SLC26A4 gene were compared with 100 unrelated subjects to exclude common polymorphism. Splice-site mutation was further confirmed by restriction enzyme length polymorphism (RFLP) with the specifically designed primers. RESULTS The proband presented with typical features of bilateral sensorineural deafness since childhood and goiter development in the early adulthood. Thyroid studies disclosed euthyroidism with elevated thyroglobulin, but negative for PDT. Marked enlargement of bilateral vestibular aqueduct (>1.5 mm) was found by CT of the temporal bone. A novel SLC26A4 splice-site mutation c.1263+1G>A (IVS10+1G>A) was identified in compound heterozygosity with the missense mutation c.1079C>T (p.A360V) in the proband. Both mutations were not found in the 100 unrelated Chinese. CONCLUSIONS Our results support previous findings that Pendred syndrome can be caused by compound heterozygous mutation in the SLC26A4 gene, in which IVS10+1G>A is a novel pathogenic mutation.
Collapse
MESH Headings
- Asian People/genetics
- Case-Control Studies
- China
- DNA Mutational Analysis
- Female
- Genetic Predisposition to Disease
- Goiter, Nodular/diagnosis
- Goiter, Nodular/ethnology
- Goiter, Nodular/genetics
- Hearing Loss, Sensorineural/diagnosis
- Hearing Loss, Sensorineural/ethnology
- Hearing Loss, Sensorineural/genetics
- Heterozygote
- Humans
- Male
- Membrane Transport Proteins/genetics
- Mutation, Missense/genetics
- Pedigree
- Perchlorates
- Polymorphism, Genetic
- Polymorphism, Restriction Fragment Length
- Reference Values
- Sequence Analysis, DNA
- Sulfate Transporters
- Tomography, X-Ray Computed
Collapse
Affiliation(s)
- Chun-Jui Huang
- Division of Endocrinology & Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
9
|
Pesce L, Bizhanova A, Caraballo JC, Westphal W, Butti ML, Comellas A, Kopp P. TSH regulates pendrin membrane abundance and enhances iodide efflux in thyroid cells. Endocrinology 2012; 153:512-21. [PMID: 22109890 PMCID: PMC3249672 DOI: 10.1210/en.2011-1548] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Thyroid hormones are essential for normal development and metabolism. Their synthesis requires transport of iodide into thyroid follicles. The mechanisms involving the apical efflux of iodide into the follicular lumen are poorly elucidated. The discovery of mutations in the SLC26A4 gene in patients with Pendred syndrome (congenital deafness, goiter, and defective iodide organification) suggested a possible role for the encoded protein, pendrin, as an apical iodide transporter. We determined whether TSH regulates pendrin abundance at the plasma membrane and whether this influences iodide efflux. Results of immunoblot and immunofluorescence experiments reveal that TSH and forskolin rapidly increase pendrin abundance at the plasma membrane through the protein kinase A pathway in PCCL-3 rat thyroid cells. The increase in pendrin membrane abundance correlates with a decrease in intracellular iodide as determined by measuring intracellular (125)iodide and can be inhibited by specific blocking of pendrin. Elimination of the putative protein kinase A phosphorylation site T717A results in a diminished translocation to the membrane in response to forskolin. These results demonstrate that pendrin translocates to the membrane in response to TSH and suggest that it may have a physiological role in apical iodide transport and thyroid hormone synthesis.
Collapse
Affiliation(s)
- Liuska Pesce
- Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, Illinois 60611, USA
| | | | | | | | | | | | | |
Collapse
|
10
|
Iwata T, Yoshida T, Teranishi M, Murata Y, Hayashi Y, Kanou Y, Griffith AJ, Nakashima T. Influence of dietary iodine deficiency on the thyroid gland in Slc26a4-null mutant mice. Thyroid Res 2011; 4:10. [PMID: 21689387 PMCID: PMC3141755 DOI: 10.1186/1756-6614-4-10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 06/20/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pendred syndrome (PDS) is an autosomal recessive disorder characterized by sensorineural hearing impairment and variable degree of goitrous enlargement of the thyroid gland with a partial defect in iodine organification. The thyroid function phenotype can range from normal function to overt hypothyroidism. It is caused by loss-of-function mutations in the SLC26A4 (PDS) gene. The severity of the goiter has been postulated to depend on the amount of dietary iodine intake. However, direct evidence has not been shown to support this hypothesis. Because Slc26a4-null mice have deafness but do not develop goiter, we fed the mutant mice a control diet or an iodine-deficient diet to evaluate whether iodine deficiency is a causative environmental factor for goiter development in PDS. METHODS We evaluated the thyroid volume in histological sections with the use of three-dimensional reconstitution software, we measured serum levels of total tri-iodothyronine (TT3) and total thyroxine (TT4) levels, and we studied the thyroid gland morphology by transmission electron microscopy. RESULTS TT4 levels became low but TT3 levels did not change significantly after eight weeks of an iodine-deficient diet compared to levels in the control diet animals. Even in Slc26a4-null mice fed an iodine-deficient diet, the volume of the thyroid gland did not increase although the size of each epithelial cell increased with a concomitant decrease of thyroid colloidal area. CONCLUSIONS An iodine-deficient diet did not induce goiter in Slc26a4-null mice, suggesting that other environmental, epigenetic or genetic factors are involved in goiter development in PDS.
Collapse
Affiliation(s)
- Tomoyuki Iwata
- Department of Otorhinolaryngology Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Kopp P, Bizhanova A. Clinical and molecular characteristics of Pendred syndrome. ANNALES D'ENDOCRINOLOGIE 2011; 72:88-94. [PMID: 21511235 DOI: 10.1016/j.ando.2011.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Pendred syndrome is an autosomal recessive disorder defined by sensorineural deafness, goiter and a partial defect in the organification of iodide. It is caused by biallelic mutations in the SLC26A4 gene, which encodes pendrin, a multifunctional anion exchanger. At the level of the inner ear, pendrin is important for the creation of a normal endolymph composition and the maintenance of the endocochlear potential. In the thyroid, pendrin is expressed at the apical membrane of thyroid follicular cells and it appears to be involved in mediating iodide efflux into the lumen and/or maintenance of the follicular pH. Goiter development and hypothyroidism vary among affected individuals and seem to be partially dependent on nutritional iodide intake. In the kidney, pendrin functions as a chloride/bicarbonate exchanger. Elucidation of the molecular basis of Pendred syndrome and the function of pendrin has provided unexpected novel insights into the pathophysiology of the inner ear, thyroid hormone synthesis, and chloride/bicarbonate exchange in the kidney.
Collapse
Affiliation(s)
- P Kopp
- Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago IL60611, USA.
| | | |
Collapse
|
12
|
Bizhanova A, Kopp P. Controversies Concerning the Role of Pendrin as an Apical Iodide Transporter in Thyroid Follicular Cells. Cell Physiol Biochem 2011; 28:485-90. [DOI: 10.1159/000335103] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2011] [Indexed: 11/19/2022] Open
|
13
|
King KA, Choi BY, Zalewski C, Madeo AC, Manichaikul A, Pryor SP, Ferruggiaro A, Eisenman D, Kim HJ, Niparko J, Thomsen J, Butman JA, Griffith AJ, Brewer CC. SLC26A4 genotype, but not cochlear radiologic structure, is correlated with hearing loss in ears with an enlarged vestibular aqueduct. Laryngoscope 2010; 120:384-9. [PMID: 19998422 PMCID: PMC2811762 DOI: 10.1002/lary.20722] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES/HYPOTHESIS Identify correlations among SLC26A4 genotype, cochlear structural anomalies, and hearing loss associated with enlargement of the vestibular aqueduct (EVA). STUDY DESIGN Prospective cohort survey, National Institutes of Health, Clinical Center, a federal biomedical research facility. METHODS Eighty-three individuals, 11 months to 59 years of age, with EVA in at least one ear were studied. Correlations among pure-tone hearing thresholds, number of mutant SLC26A4 alleles, and the presence of cochlear anomalies detected by computed tomography or magnetic resonance imaging were examined. RESULTS Linear mixed-effects model indicated significantly poorer hearing in ears with EVA in individuals with two mutant alleles of SLC26A4 than in those with EVA and a single mutant allele (P = .012) or no mutant alleles (P = .007) in this gene. There was no detectable relationship between degree of hearing loss and the presence of structural cochlear anomalies. CONCLUSIONS The number of mutant alleles of SLC26A4, but not the presence of cochlear anomalies, has a significant association with severity of hearing loss in ears with EVA. This information will be useful for prognostic counseling of patients and families with EVA.
Collapse
Affiliation(s)
- Kelly A. King
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
- Hearing and Speech Sciences Department, University of Maryland, College Park, Maryland, USA
| | - Byung Yoon Choi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
| | - Christopher Zalewski
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
| | - Anne C. Madeo
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ani Manichaikul
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Shannon P. Pryor
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
| | - Anne Ferruggiaro
- Hearing and Speech Sciences Department, University of Maryland, College Park, Maryland, USA
| | - David Eisenman
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - H. Jeffrey Kim
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
- Department of Otolaryngology-Head and Neck Surgery, Georgetown University Hospital, Washington, DC, USA
| | - John Niparko
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - James Thomsen
- Pediatric Ear, Nose and Throat of Atlanta, Atlanta, Georgia, USA
| | - John A. Butman
- Diagnostic Radiology Department, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Andrew J. Griffith
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
| | - Carmen C. Brewer
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA
| |
Collapse
|
14
|
Vázquez AGM, Montesinos IG, Jiménez AM, García JAR, García JG, Hernández JA. [Pendred's syndrome: a cause of goiter associated with deafness]. ACTA ACUST UNITED AC 2009; 56:428-30. [PMID: 19959154 DOI: 10.1016/s1575-0922(09)72714-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 09/07/2009] [Indexed: 11/28/2022]
Abstract
Pendred's syndrome is an autosomal recessive disorder leading to congenital sensorineural hearing loss and a variable degree of goiter due to reduced iodine organification. The cause of this disease is dysfunction of an anion transporter protein located on the apical membrane of thyrocytes, called pendrin, which is also found in the kidney and cochlea. Molecular analysis of the gene is useful to identify other affected family members and provide proper genetic advice and early diagnosis in descendants. We present the cases of two siblings with sensorineural deafness who were diagnosed with Pendred's syndrome as adults because one of them consulted for goiter.
Collapse
|
15
|
|
16
|
Mimura T, Sato E, Sugiura M, Yoshino T, Naganawa S, Nakashima T. Hearing loss in patients with enlarged vestibular aqueduct: Air-bone gap and audiological Bing test. Int J Audiol 2009; 44:466-9. [PMID: 16149241 DOI: 10.1080/14992020500057665] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The Bing test is based on the principle that occlusion of the external auditory meatus improves the perception of bone-conducted sounds unless there is a conductive hearing impairment. An air-bone gap has been reported in patients with large vestibular aqueduct (LVA) syndrome without apparent middle ear dysfunction. We therefore performed the Bing test on nine patients with this syndrome to evaluate whether it is associated with an air-bone gap or middle ear dysfunction. Bone conduction thresholds did not change significantly during the Bing test in any patient. Because an air-bone gap is observed in patients with abnormal communication between the inner ear and cerebrospinal fluid through the LVA, dehiscent superior canal, or dilated inner ear meatus; we propose that a 'three windows' model (in which the abnormal communication provided by the enlarged endolymphatic duct and sac in LVA acts as the 'third window' for sound conductance) might explain the air-bone gap in such patients.
Collapse
Affiliation(s)
- Tamie Mimura
- Department of Otorhinolaryngology, Nagoya University School of Medicine, Nagoya, Japan.
| | | | | | | | | | | |
Collapse
|
17
|
Li J, Zhang F, Gao J, Cai Z, Zhao Q, Xing Y, Xu J, Liu Y, Shao L, Che R, Wei Z, He L. An association study of the SLC26A4 gene in children with mental retardation. Neurosci Lett 2009; 457:155-8. [DOI: 10.1016/j.neulet.2009.03.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 03/22/2009] [Accepted: 03/27/2009] [Indexed: 10/20/2022]
|
18
|
Bizhanova A, Kopp P. Minireview: The sodium-iodide symporter NIS and pendrin in iodide homeostasis of the thyroid. Endocrinology 2009; 150:1084-90. [PMID: 19196800 PMCID: PMC2654752 DOI: 10.1210/en.2008-1437] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Thyroid hormones are essential for normal development and metabolism. Thyroid hormone biosynthesis requires iodide uptake into the thyrocytes and efflux into the follicular lumen, where it is organified on selected tyrosyls of thyroglobulin. Uptake of iodide into the thyrocytes is mediated by an intrinsic membrane glycoprotein, the sodium-iodide symporter (NIS), which actively cotransports two sodium cations per each iodide anion. NIS-mediated transport of iodide is driven by the electrochemical sodium gradient generated by the Na(+)/K(+)-ATPase. NIS is expressed in the thyroid, the salivary glands, gastric mucosa, and the lactating mammary gland. TSH and iodide regulate iodide accumulation by modulating NIS activity via transcriptional and posttranscriptional mechanisms. Biallelic mutations in the NIS gene lead to a congenital iodide transport defect, an autosomal recessive condition characterized by hypothyroidism, goiter, low thyroid iodide uptake, and a low saliva/plasma iodide ratio. Pendrin is an anion transporter that is predominantly expressed in the inner ear, the thyroid, and the kidney. Biallelic mutations in the SLC26A4 gene lead to Pendred syndrome, an autosomal recessive disorder characterized by sensorineural deafness, goiter, and impaired iodide organification. In thyroid follicular cells, pendrin is expressed at the apical membrane. Functional in vitro data and the impaired iodide organification observed in patients with Pendred syndrome support a role of pendrin as an apical iodide transporter.
Collapse
Affiliation(s)
- Aigerim Bizhanova
- Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | | |
Collapse
|
19
|
Kopp P, Pesce L, Solis-S JC. Pendred syndrome and iodide transport in the thyroid. Trends Endocrinol Metab 2008; 19:260-8. [PMID: 18692402 DOI: 10.1016/j.tem.2008.07.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Revised: 07/07/2008] [Accepted: 07/08/2008] [Indexed: 01/05/2023]
Abstract
Pendred syndrome is an autosomal recessive disorder characterized by sensorineural hearing impairment, presence of goiter, and a partial defect in iodide organification, which may be associated with insufficient thyroid hormone synthesis. Goiter development and development of hypothyroidism are variable and depend on nutritional iodide intake. Pendred syndrome is caused by biallelic mutations in the SLC26A4 gene, which encodes pendrin, a transporter of chloride, bicarbonate and iodide. This review discusses the controversies surrounding the potential role of pendrin in mediating apical iodide efflux into the lumen of thyroid follicles, and discusses its functional role in the kidney and the inner ear.
Collapse
Affiliation(s)
- Peter Kopp
- Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60614, USA.
| | | | | |
Collapse
|
20
|
Suzuki H, Oshima A, Tsukamoto K, Abe S, Kumakawa K, Nagai K, Satoh H, Kanda Y, Iwasaki S, Usami SI. Clinical characteristics and genotype-phenotype correlation of hearing loss patients with SLC26A4 mutations. Acta Otolaryngol 2007; 127:1292-7. [PMID: 17851929 DOI: 10.1080/00016480701258739] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
CONCLUSIONS The present study confirmed the clinical characteristics of patients with SLC26A4 mutations: congenital, fluctuating, and progressive hearing loss usually associated with vertigo and/or goiter during long-term follow-up. This clarification should help to facilitate appropriate genetic counseling and proper medical management for patients with these mutations, but there was no particular genotype-phenotype correlation among them, suggesting that other factors may contribute to such variability. OBJECTIVES Due to the wide range of phenotypes caused by SLC26A4 mutations, there is controversy with regard to genotype-phenotype correlation. The present study was performed: (1) to determine phenotypic range in patients with biallelic SLC26A4 mutations, and (2) to evaluate whether possible genotype-phenotype correlation exists. SUBJECTS AND METHODS Phenotypes in 39 hearing loss patients with SLC26A4 mutations were summarized and genotype-phenotype correlation was analyzed. RESULTS Hearing level varied in the individuals from mild to profound severity. Most of the patients had fluctuating and progressive hearing loss that may have been of prelingual onset. Twenty-four (70.6%) patients had episodes of vertigo, and 10 (27.8%) patients had goiter, which had appeared at age 12 or older. In contrast to such phenotypic variabilities, no apparent correlation was found between these phenotypes and their genotypes.
Collapse
Affiliation(s)
- Hiroaki Suzuki
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Lai CC, Chiu CY, Shiao AS, Tso YC, Wu YC, Tu TY, Jap TS. Analysis of the SLC26A4 gene in patients with Pendred syndrome in Taiwan. Metabolism 2007; 56:1279-84. [PMID: 17697873 DOI: 10.1016/j.metabol.2007.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 05/22/2007] [Indexed: 10/23/2022]
Abstract
Pendred syndrome (PS) is an autosomal recessive disease that is characterized by congenital sensorineural hearing loss, goiter, and a partial iodine organification defect. In this study, we characterized the thyroid status and identified mutations in the SLC26A4 gene in Chinese subjects with PS. We evaluated 7 unrelated Chinese subjects who had PS. Biochemical analysis, formal audiogram, ultrasonography of the thyroid gland, perchlorate discharge test, computerized tomography scan of the vestibular aqueducts, and DNA sequence analysis of SLC26A4 were performed. Levels of thyroid hormones were essentially normal in all patients: 2 patients had goiters and/or elevated serum thyroglobulin levels, whereas 2 other patients had positive thyroid antibodies and a positive perchlorate discharge test. We identified SLC26A4 gene mutations in 6 of 7 probands and their affected relatives. The affected subjects in family I was compound heterozygous for 2 missense mutations: a mutation in exon 9 (1079C>T) that resulted in the replacement of alanine by valine at codon 360 (A360V) and a mutation in exon 19 (2168A>G) that resulted in the replacement of histidine by arginine at codon 723 (H723R). The affected subjects in families II and III all were homozygous for a mutation in intron 7. The probands IV and V were compound heterozygotes for the mutation in intron 7 and in exon 19, and the proband VI was compound heterozygous for the intron 7 mutation and a missense mutation in exon 12 (1343C>T) that resulted in the replacement of serine by leucine at codon 448 (S448L). One novel mutation was identified (A360V). We identified biallelic mutations in the SLC26A4 gene in 6 of 7 probands with PS in Taiwan, including a novel missense mutation. The mild thyroid dysfunction in these patients suggests that PS should be considered in all patients with congenital or early-onset hearing impairment.
Collapse
Affiliation(s)
- Chien-Chung Lai
- Division of Otorhinolaryngology, Department of Surgery, Taipei City Hospital, Taipei, Taiwan, ROC
| | | | | | | | | | | | | |
Collapse
|
22
|
Fitoz S, Sennaroğlu L, Incesulu A, Cengiz FB, Koç Y, Tekin M. SLC26A4 mutations are associated with a specific inner ear malformation. Int J Pediatr Otorhinolaryngol 2007; 71:479-86. [PMID: 17197040 DOI: 10.1016/j.ijporl.2006.11.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Accepted: 11/28/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND AIM Inner ear anomalies have been reported in approximately 30% of children with early onset deafness. Identification of causative genetic factors in a large proportion of these patients was not successful. Mutations in the SLC26A4 gene have been detected in individuals with enlarged vestibular aqueduct (EVA) or Mondini dysplasia. We aimed to characterize the inner ear anomalies associated with SLC26A4 mutations. METHODS The SLC26A4 gene has been screened for mutations in 16 subjects from 14 unrelated Turkish families with a variety of inner ear anomalies ranging from Michel aplasia to incomplete partition-II and EVA. None of the patients was diagnosed to have a recognizable genetic syndrome. Additional four patients with Pendred syndrome from three families were included. RESULTS Only one patient with EVA was found to have a heterozygous mutation (c.1586delT) in SLC26A4. All patients with Pendred syndrome had homozygous mutations and were noted to have either EVA or EVA associated with incomplete partition-II on the computed tomography of the temporal bone. CONCLUSION SLC26A4 mutations are not associated with a large spectrum of inner ear anomalies. They, instead, result in a specific morphological appearance consistent with EVA or incomplete partition-II.
Collapse
Affiliation(s)
- Suat Fitoz
- Department of Radiodiagnostics, Ankara University School of Medicine, Ankara, Turkey
| | | | | | | | | | | |
Collapse
|
23
|
Sugiura M, Sato E, Nakashima T, Sugiura J, Furuhashi A, Yoshino T, Nakayama A, Mori N, Murakami H, Naganawa S. Long-term follow-up in patients with Pendred syndrome: vestibular, auditory and other phenotypes. Eur Arch Otorhinolaryngol 2005; 262:737-43. [PMID: 15747138 DOI: 10.1007/s00405-004-0884-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Accepted: 09/23/2004] [Indexed: 10/25/2022]
Abstract
Fourteen patients with a Pendred syndrome gene (Pds) mutation and three patients without the mutation were studied to evaluate long-term vestibular and auditory manifestations among patients with bilateral enlarged vestibular aqueducts (EVA). Charts were reviewed retrospectively for age, gender, otological history, presence or absence of vertigo, results of magnetic resonance imaging, relevant gene mutations and perchlorate discharge test. A missense mutation, His 723 Arg (H723R), was identified in the homozygous state in six patients and in the heterozygous state in seven patients. Another missense mutation, Tyr 410 Met (T410 M), was identified in the heterozygous state in one patient. Patients with vertigo tended to have hearing fluctuation, compared with the patients without vertigo. Patients homozygous for H723R tended to have more episodes of vertigo than the heterozygous individuals. Only one patient who was homozygous for H723R had goiter. The long-term outcome of hearing level in patients with the H723R mutation was significantly better compared with published results for patients with a Pds mutation, but not for those with the H723R mutation. Whether environmental factors or a subtype of the Pds mutation H723R are related to the long-term outcome for these patients must be clarified.
Collapse
Affiliation(s)
- Makoto Sugiura
- Department of Otorhinolaryngology, Nagoya University School of Medicine, 466-8550 Nagoya, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Park HJ, Lee SJ, Jin HS, Lee JO, Go SH, Jang HS, Moon SK, Lee SC, Chun YM, Lee HK, Choi JY, Jung SC, Griffith AJ, Koo SK. Genetic basis of hearing loss associated with enlarged vestibular aqueducts in Koreans. Clin Genet 2004; 67:160-5. [PMID: 15679828 DOI: 10.1111/j.1399-0004.2004.00386.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sensorineural hearing loss associated with enlargement of the vestibular aqueduct (EVA) can be associated with mutations of the SLC26A4 gene. In western populations, less than one-half of the affected individuals with EVA have two mutant SLC26A4 alleles, and EVA is frequently caused by unknown genetic or environmental factors alone or in combination with a single SLC26A4 mutation as part of a complex trait. In this study, we ascertained 26 Korean probands with EVA and performed nucleotide sequence analysis to detect SLC26A4 mutations. All subjects had bilateral EVA, and 20 of 26 were sporadic (simplex) cases. Fourteen different mutations were identified, including nine novel mutations. Five mutations were recurrent and accounted for 80% of all mutant alleles, providing a basis for the design and interpretation of cost-efficient mutation detection algorithms. Two mutant alleles were identified in 21 (81%), one mutant allele was detected in three (11%), and zero mutant allele was detected in two (8%) of 26 probands. The high proportion of Korean probands with two SLC26A4 mutations may reflect a reduced frequency of other genetic or environmental factors causing EVA in comparison to western populations.
Collapse
Affiliation(s)
- H-J Park
- Soree Ear Clinic, National Institute of Health, 5 Nokbun-dong, Eunpyung-gu, Seoul 122-701, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Napiontek U, Borck G, Müller-Forell W, Pfarr N, Bohnert A, Keilmann A, Pohlenz J. Intrafamilial variability of the deafness and goiter phenotype in Pendred syndrome caused by a T416P mutation in the SLC26A4 gene. J Clin Endocrinol Metab 2004; 89:5347-51. [PMID: 15531480 DOI: 10.1210/jc.2004-1013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pendred syndrome (PS) is the most common cause of syndromic deafness, accounting for more than 5% of all autosomal-recessive hearing loss cases. It is characterized by bilateral sensorineural hearing loss and by goiter with or without hypothyroidism. Mutations in the SLC26A4 gene cause both classical PS and deafness associated with an enlarged vestibular aqueduct without goiter. To investigate a possible genotype-phenotype correlation in PS, we performed a detailed clinical and genetic study in three adult German sibs with typical PS caused by a common homozygous SLC26A4 mutation, T416P. An audiological long-term follow-up of 23 yr showed that the mutation T416P is associated with a distinct type of hearing loss in each of the three sibs: moderate-to-profound progressive deafness, profound nonprogressive deafness, and a milder but more rapidly progressing form. We show that these phenotypic differences are not caused by either different degrees of inner ear malformations or sequence variations in the GJB2/connexin 26 gene. Because the thyroid phenotype was also highly variable within the family, with thyroid sizes ranging from normal to large goiters requiring thyroidectomy, this study leads to the conclusion that other environmental and/or genetic factors have an impact on the PS phenotype.
Collapse
Affiliation(s)
- Ulrike Napiontek
- Department of Communication Disorders, Hospitals of the Johannes Gutenberg University of Mainz, Langenbeckstrasse 1, Building 109, D-55101 Mainz, Germany
| | | | | | | | | | | | | |
Collapse
|
26
|
Bogazzi F, Russo D, Raggi F, Ultimieri F, Berrettini S, Forli F, Grasso L, Ceccarelli C, Mariotti S, Pinchera A, Bartalena L, Martino E. Mutations in the SLC26A4 (pendrin) gene in patients with sensorineural deafness and enlarged vestibular aqueduct. J Endocrinol Invest 2004; 27:430-5. [PMID: 15279074 DOI: 10.1007/bf03345286] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Pendred syndrome and the enlarged vestibular aqueduct (EVA) are considered phenotypic variations of the same entity due to mutations in the SLC26A4 (pendrin) gene. Pendred syndrome consists in sensorineural deafness, goiter and impaired thyroid hormone synthesis while in EVA thyroid function seems to be preserved. The aim of this study was to evaluate thyroid function and morphology and to look for mutations in the SLC26A4 gene in patients presented with EVA. Among 57 consecutive patients with sensorineural deafness 15 with EVA, as assessed by magnetic resonance imaging (MRI), were identified and studied. A complete evaluation of thyroid function including thyroid echography and perchlorate discharge test was carried out in all patients with EVA; all exons of the SLC26A4 gene were amplified from peripheral leukocytes and directly sequenced, using specific intronic primers. Out of 15 patients with EVA, goiter was present in 8 (53%), hypothyroidism in 7 (47%), increased serum thyroglobulin levels in 8 (53%) and a positive perchlorate discharge test in 10 (67%). Nine alleles of the SLC26A4 gene were mutated: 2 novel mutations (L465W and G497R) and 4 already known mutations (T410M, R409H, T505N and IVS1001+1G>A) were found. Four subjects were compound heterozygous and 1 heterozygous (G497R/wt). All patients harbouring mutations in the SLC26A4 gene had goiter and a positive perchlorate discharge test: 3 were slightly hypothyroid and 2 euthyroid. The remaining 10 patients had no mutations in the SLC26A4 gene: 4 of them were hypothyroid, 2 with goiter and positive perchlorate discharge test, 2 without goiter and with negative perchlorate discharge test. Two patients without mutations were euthyroid with positive perchlorate discharge test. Patients with mutations in the SLC26A4 gene had larger thyroid volume (p<0.002), higher serum thyroglobulin (Tg) levels (p<0.002) and greater radioiodine discharge after perchlorate (p=0.09) than patients without mutations. The results of the present study lend support to the concept that all patients with mutated SLC26A4 gene have abnormalities of thyroid function tests.
Collapse
Affiliation(s)
- F Bogazzi
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Naganawa S, Koshikawa T, Fukatsu H, Ishigaki T, Sato E, Sugiura M, Yoshino T, Nakashima T. Enlarged endolymphatic duct and sac syndrome: relationship between MR findings and genotype of mutation in pendred syndrome gene. Magn Reson Imaging 2004; 22:25-30. [PMID: 14972391 DOI: 10.1016/j.mri.2003.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2003] [Revised: 07/21/2003] [Accepted: 07/22/2003] [Indexed: 11/18/2022]
Abstract
Pendred syndrome (PDS) is characterized by profound deafness in childhood, positive perchlorate challenge, and goiter. PDS is often associated with enlarged endolymphatic duct and sac (EEDS), and recently, PDS gene mutations have been reported even in those patients with EEDS without classic Pendred syndrome. In a previous report, the number of mutant alleles was correlated with the degree of subclinical thyroid abnormality, but not with hearing loss, in patients with missense mutation H723R. It also has been reported that the hearing loss in EEDS was not correlated with the EEDS volume, cochlear modiolar area, or signal intensity of the endolymphatic sac. We evaluated the correlations between the number of mutant alleles and these parameters in patients with EEDS to investigate the mechanisms underlying this condition. The study group was comprised of 16 Japanese patients with EEDS diagnosed by MR imaging. The H723R mutation was homozygous in six patients and heterozygous in six patients, with no mutation found in four patients. The modiolar area, EEDS volume, and signal intensity ratio (sac signal/cerebrospinal fluid signal) were not significantly correlated with the number of mutant alleles. PDS gene mutations may not be the only cause of EEDS, and the mechanisms underlying EEDS remain unclear.
Collapse
Affiliation(s)
- Shinji Naganawa
- Department of Radiology, Nagoya University School of Medicine, Nagoya, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Tekin M, Akçayöz D, Comak E, Boğoçlu G, Duman T, Fitoz S, Ilhan I, Akar N. Screening the SLC26A4 gene in probands with deafness and goiter (Pendred syndrome) ascertained from a large group of students of the schools for the deaf in Turkey. Clin Genet 2003; 64:371-4. [PMID: 12974744 DOI: 10.1034/j.1399-0004.2003.00144.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
29
|
Park HJ, Shaukat S, Liu XZ, Hahn SH, Naz S, Ghosh M, Kim HN, Moon SK, Abe S, Tukamoto K, Riazuddin S, Kabra M, Erdenetungalag R, Radnaabazar J, Khan S, Pandya A, Usami SI, Nance WE, Wilcox ER, Riazuddin S, Griffith AJ. Origins and frequencies of SLC26A4 (PDS) mutations in east and south Asians: global implications for the epidemiology of deafness. J Med Genet 2003; 40:242-8. [PMID: 12676893 PMCID: PMC1735432 DOI: 10.1136/jmg.40.4.242] [Citation(s) in RCA: 243] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Recessive mutations of SLC26A4 (PDS) are a common cause of Pendred syndrome and non-syndromic deafness in western populations. Although south and east Asia contain nearly one half of the global population, the origins and frequencies of SLC26A4 mutations in these regions are unknown. We PCR amplified and sequenced seven exons of SLC26A4 to detect selected mutations in 274 deaf probands from Korea, China, and Mongolia. A total of nine different mutations of SLC26A4 were detected among 15 (5.5%) of the 274 probands. Five mutations were novel and the other four had seldom, if ever, been identified outside east Asia. To identify mutations in south Asians, 212 Pakistani and 106 Indian families with three or more affected offspring of consanguineous matings were analysed for cosegregation of recessive deafness with short tandem repeat markers linked to SLC26A4. All 21 SLC26A4 exons were PCR amplified and sequenced in families segregating SLC26A4 linked deafness. Eleven mutant alleles of SLC26A4 were identified among 17 (5.4%) of the 318 families, and all 11 alleles were novel. SLC26A4 linked haplotypes on chromosomes with recurrent mutations were consistent with founder effects. Our observation of a diverse allelic series unique to each ethnic group indicates that mutational events at SLC26A4 are common and account for approximately 5% of recessive deafness in south Asians and other populations.
Collapse
Affiliation(s)
- H-J Park
- Section on Gene Structure and Function, National Institutes of Health, Rockville, Maryland 20850, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|