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Abstract
OBJECTIVE To describe the genetic and phenotypic spectrum of Usher syndrome after 6 years of studies by next-generation sequencing, and propose an up-to-date classification of Usher genes in patients with both visual and hearing impairments suggesting Usher syndrome, and in patients with seemingly isolated deafness. STUDY DESIGN The systematic review and meta-analysis protocol was based on Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed 1) a meta-analysis of data from 11 next-generation sequencing studies in 684 patients with Usher syndrome; 2) a meta-analysis of data from 21 next-generation studies in 2,476 patients with seemingly isolated deafness, to assess the involvement of Usher genes in seemingly nonsyndromic hearing loss, and thus the proportion of patients at high risk of subsequent retinitis pigmentosa (RP); 3) a statistical analysis of differences between parts 1) and 2). RESULTS In patients with both visual and hearing impairments, the biallelic disease-causing mutation rate was assessed for each Usher gene to propose a classification by frequency: USH2A: 50% (341/684) of patients, MYO7A: 21% (144/684), CDH23: 6% (39/684), ADGRV1: 5% (35/684), PCDH15: 3% (21/684), USH1C: 2% (17/684), CLRN1: 2% (14/684), USH1G: 1% (9/684), WHRN: 0.4% (3/684), PDZD7 0.1% (1/684), CIB2 (0/684). In patients with seemingly isolated sensorineural deafness, 7.5% had disease-causing mutations in Usher genes, and are therefore at high risk of developing RP. These new findings provide evidence that usherome dysfunction is the second cause of genetic sensorineural hearing loss after connexin dysfunction. CONCLUSION These results promote generalization of early molecular screening for Usher syndrome in deaf children.
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Smith CEL, Poulter JA, Levin AV, Capasso JE, Price S, Ben-Yosef T, Sharony R, Newman WG, Shore RC, Brookes SJ, Mighell AJ, Inglehearn CF. Spectrum of PEX1 and PEX6 variants in Heimler syndrome. Eur J Hum Genet 2016; 24:1565-1571. [PMID: 27302843 PMCID: PMC5026821 DOI: 10.1038/ejhg.2016.62] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 04/12/2016] [Accepted: 04/27/2016] [Indexed: 12/30/2022] Open
Abstract
Heimler syndrome (HS) consists of recessively inherited sensorineural hearing loss, amelogenesis imperfecta (AI) and nail abnormalities, with or without visual defects. Recently HS was shown to result from hypomorphic mutations in PEX1 or PEX6, both previously implicated in Zellweger Syndrome Spectrum Disorders (ZSSD). ZSSD are a group of conditions consisting of craniofacial and neurological abnormalities, sensory defects and multi-organ dysfunction. The finding of HS-causing mutations in PEX1 and PEX6 shows that HS represents the mild end of the ZSSD spectrum, though these conditions were previously thought to be distinct nosological entities. Here, we present six further HS families, five with PEX6 variants and one with PEX1 variants, and show the patterns of Pex1, Pex14 and Pex6 immunoreactivity in the mouse retina. While Ratbi et al. found more HS-causing mutations in PEX1 than in PEX6, as is the case for ZSSD, in this cohort PEX6 variants predominate, suggesting both genes play a significant role in HS. The PEX6 variant c.1802G>A, p.(R601Q), reported previously in compound heterozygous state in one HS and three ZSSD cases, was found in compound heterozygous state in three HS families. Haplotype analysis suggests a common founder variant. All families segregated at least one missense variant, consistent with the hypothesis that HS results from genotypes including milder hypomorphic alleles. The clinical overlap of HS with the more common Usher syndrome and lack of peroxisomal abnormalities on plasma screening suggest that HS may be under-diagnosed. Recognition of AI is key to the accurate diagnosis of HS.
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Affiliation(s)
- Claire E L Smith
- Leeds Institute of Biomedical and Clinical Sciences, St. James's University Hospital, University of Leeds, Leeds, UK
| | - James A Poulter
- Leeds Institute of Biomedical and Clinical Sciences, St. James's University Hospital, University of Leeds, Leeds, UK
| | - Alex V Levin
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA.,Children's Hospital of the King's Daughters, Norfolk, VA, USA.,Pediatric Ophthalmology and Ocular Genetics, Philadelphia, PA, USA
| | - Jenina E Capasso
- Pediatric Ophthalmology and Ocular Genetics, Philadelphia, PA, USA
| | - Susan Price
- Department of Clinical Genetics, Northampton General Hospital, NHS Trust, Northampton, UK
| | | | - Reuven Sharony
- The Genetic Institute and Obstetrics and Gynaecology Department, Meir Medical Center, Kfar Saba, Israel
| | - William G Newman
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester Academic Health Sciences Centre, Manchester, UK.,Manchester Centre for Genomic Medicine, Institute of Human Development, University of Manchester, Manchester, UK
| | - Roger C Shore
- School of Dentistry, Department of Oral Biology, St. James's University Hospital, University of Leeds, Leeds, UK
| | - Steven J Brookes
- School of Dentistry, Department of Oral Biology, St. James's University Hospital, University of Leeds, Leeds, UK
| | - Alan J Mighell
- Leeds Institute of Biomedical and Clinical Sciences, St. James's University Hospital, University of Leeds, Leeds, UK.,Department of Oral Medicine, School of Dentistry, University of Leeds, Leeds, UK
| | - Chris F Inglehearn
- Leeds Institute of Biomedical and Clinical Sciences, St. James's University Hospital, University of Leeds, Leeds, UK
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Alonso V, Caserio M. A Clinical Study of Direct Composite Full-Coverage Crowns: Long-Term Results. Oper Dent 2012; 37:432-41. [DOI: 10.2341/11-229-s] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective
Long-term assessment of the clinical behavior of direct composite full-coverage crowns using transparent strip crowns as a matrix.
Method
A retrospective observational study without controls of 21 restorations was performed: nine teeth with hypoplasia, six conoid teeth, and six with microdontia. The mean patient age was 22.5 ± 8.2 years. The clinical procedure consisted of cleaning the tooth, acid etching and application of adhesive, after which a transparent strip crown was filled with composite and placed on the tooth. The gingival contour was polished using multifluted burs and interproximal spaces polished with polishing strips. Patients were examined after a period of 12.5 (±4.6) years by two observers who recorded the plaque index and evaluated the restorations in accordance with the modified U. S. Public Health Service (USPHS) criteria.
Results
Except for one case, all the scores obtained on the basis of the USPHS criteria were within the acceptable range. There were no cases of secondary caries. The statistically significant variations were anatomical form, marginal adaptation, marginal discolouration, and surface roughness.
Discussion
This technique is simple and noninvasive. It is a viable long-term treatment option for teeth with amelogenesis or microdonts and is especially suitable for patients still undergoing growth.
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