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Usher Syndrome (usher + syndrome)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Mutation spectrum of MYO7A and evaluation of a novel nonsyndromic deafness DFNB2 allele with residual function,,

HUMAN MUTATION, Issue 4 2008
Saima Riazuddin
Abstract Recessive mutations of MYO7A, encoding unconventional myosin VIIA, can cause either a deaf-blindness syndrome (type 1 Usher syndrome; USH1B) or nonsyndromic deafness (DFNB2). In our study, deafness segregating as a recessive trait in 24 consanguineous families showed linkage to markers for the DFNB2/USH1B locus on chromosome 11q13.5. A total of 23 of these families segregate USH1 due to 17 homozygous mutant MYO7A alleles, of which 14 are novel. One family segregated nonsyndromic hearing loss DFNB2 due to a novel three-nucleotide deletion in an exon of MYO7A (p.E1716del) encoding a region of the tail domain. We hypothesized that DFNB2 alleles of MYO7A have residual myosin VIIA. To address this question we investigated the effects of several mutant alleles by making green fluorescent protein (GFP) tagged cDNA expression constructs containing engineered mutations of mouse Myo7a at codons equivalent to pathogenic USH1B and DFNB2 alleles of human MYO7A. We show that in transfected mouse hair cells an USH1B mutant GFP-myosin VIIa does not localize properly to inner ear hair cell stereocilia. However, a GFP-myosin VIIa protein engineered to have an equivalent DFNB2 mutation to p.E1716del localizes correctly in transfected mouse hair cells. This finding is consistent with the hypothesis that p.E1716del causes a less severe phenotype (DFNB2) than the USH1B -associated alleles because the resulting protein retains some degree of normal function. Hum Mutat 29(4), 502,511, 2008. Published 2008 Wiley-Liss, Inc. [source]

Sensory impairments, intellectual disability and psychiatry

JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 6 2001
S. Carvill
Abstract The present review looks at: (1) prevalence studies of sensory impairments in people with intellectual disability (ID); (2) studies looking at psychological and psychiatric disorders in people with sensory impairments; and (3) studies that have examined the association of sensory impairments with autism. Research has indicated that sensory impairments are more common in people with ID. Psychiatric disorders are believed to be more common in children with visual impairment (VI) when associated with other handicaps. Some authors believe that hearing impairment (HI) can result in personality disorders. Studies have also shown a higher prevalence of psychiatric disorders in children with HI and a higher incidence of deaf people in psychiatric hospitals than in the general population. Psychiatric disorders in children with HI are particularly associated with low IQ and low communication ability, especially in those with multiple handicaps. There is little evidence for a higher incidence of schizophrenia in people with HI. Blind people demonstrate many autistic-like features and there has been discussion in the literature as to their cause. Deaf people also demonstrate some similar features to those in autism, but an association with autism has not been conclusively made. Deaf-blind people commonly demonstrate problem behaviour (e.g. self-injury). Usher syndrome, which is the most common cause of deaf-blindness, is associated with psychiatric disorders, particularly psychosis. The need for assessment of sensory functioning in people with ID, the difficulties inherent in this and the need for specialist services is stressed. [source]

Immunohistochemistry and Reverse Transcriptase,Polymerase Chain Reaction as Methods for Diagnostic Determination of Usher Syndrome Type IIa,

THE LARYNGOSCOPE, Issue 7 2004
Edward Cohn
Abstract Objectives/Hypothesis: Patients having null mutations in the USH2A gene do not produce usherin and therefore are not positive for immunohistochemical staining of the usherin protein. Thus, immunostaining for usherin can serve as a reliable diagnostic tool for Usher syndrome type IIa. Study Design: Prospective. Methods: Immunohistochemical staining for usherin was carried out in basement membrane of minor salivary gland tissue from subjects with confirmed Usher syndrome type IIa and from archival minor salivary gland tissue from patients without Usher syndrome as control samples. Quantitative usherin messenger RNA analysis was performed using minor salivary gland biopsy tissue. Results: Five subjects with Usher syndrome type IIa had no immunostaining in minor salivary gland tissue, whereas control minor salivary gland tissue did stain with usherin antibody. No usherin RNA was detected in biopsy specimens from patients with confirmed Usher syndrome IIa. Conclusion: The feasibility was confirmed of diagnosing Usher syndrome type IIa using purified usherin antibody in subjects having two null USH2A mutations. [source]

Cefuroxime-induced pemphigus erythematosus in a young boy

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2009
A. Baroni
Summary Pemphigus erythematosus (Senear,Usher syndrome) is a variant of superficial pemphigus with features of both lupus erythematosus and pemphigus. It affects mainly middle-aged adults, and is rarely observed before the age of 20 years. The case of a 14-year-old boy who showed cutaneous lesions suggestive for pemphigus erythematosus is described. Not all laboratory and histopathological investigations confirmed the hypothesis, so a diagnosis of clinical pemphigus erythematosus was made. Systemic steroid therapy was effective in controlling the disease. This case is interesting because of the rare occurrence of pemphigus erythematosus in adolescence and the possibility of another drug being added to the list of pemphigus inducers. [source]

An audit of genetic testing in diagnosis of inherited retinal disorders: a prerequisite for gene-specific intervention

CLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 7 2009
Monika Pradhan MS MRCOphth
Abstract Background:, There has been an exponential increase in the number of genes implicated in inherited retinal disease over the last decade, but the genetic and phenotypic heterogeneity limited mutation detection. The high cost of sequencing and long turn around times meant that gene testing was not a viable option, particularly in New Zealand. Recently, advancements including development of micro-array-based mutation analysis and non-for-profit laboratories have resulted in affordable and time-efficient testing. This has enabled genetic diagnostics to become an integral component of the work-up for inherited retinal disease. Methods:, Genetic testing for inherited retinal disorders was initiated via the Ocular Genetic Clinic in Auckland 2 years ago. A retrospective audit of genetic testing over this period was carried out. The results of these tests and outcomes are discussed. Results:, Thirty-five probands have undergone genetic testing for retinal disorders. This has included X-Linked Retinoschisis, Leber Congenital Amaurosis, Retinitis Pigmentosa, Albinism, Achromatopsia, Usher syndrome, Stargardt disease and Mitochondrial disease. Of these, 54% of tests (19/35) showed a rare variant or pathogenic mutation. Three couples have proceeded to investigate the options of prenatal diagnosis and/or pre-implantation genetic diagnosis. Conclusion:, The introduction of genetic testing, largely via disease arrays, has been highly successful at clarifying disease genotype in our cohort. It is now a timely and cost-effective investigation that should be elemental to the assessment of inherited retinal disease. Genetic testing in an opportune fashion permits genetic counselling, enables families to make reproductive choices and might allow the possibility of gene therapy interventions. [source]