Inframe deletion of human ESPN is associated with deafness, vestibulopathy and vision impairment
| Autor: | Saima Riazuddin, Khitab Gul, Robert A. Sisk, Sheikh Riazuddin, Lili Zheng, Gowri N. Sarangdhar, Thomas Jaworek, Shaheen N. Khan, James R. Bartles, Zubair M. Ahmed, Thomas B. Friedman |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Sanger sequencing Genetics Vestibular areflexia Usher syndrome Locus (genetics) 030105 genetics & heredity Biology Disease gene identification medicine.disease Phenotype 03 medical and health sciences symbols.namesake 030104 developmental biology Genetic linkage otorhinolaryngologic diseases symbols medicine Genetics (clinical) Exome sequencing |
| Zdroj: | Journal of Medical Genetics. 55:479-488 |
| ISSN: | 1468-6244 0022-2593 |
| Popis: | BackgroundUsher syndrome (USH) is a neurosensory disorder characterised by deafness, variable vestibular areflexia and vision loss. The aim of the study was to identify the genetic defect in a Pakistani family (PKDF1051) segregating USH.MethodsGenome-wide linkage analysis was performed by using an Illumina linkage array followed by Sanger and exome sequencing. Heterologous cells and mouse organ of Corti explant-based transfection assays were used for functional evaluations. Detailed clinical evaluations were performed to characterise the USH phenotype.ResultsThrough homozygosity mapping, we genetically linked the USH phenotype segregating in family PKDF1051 to markers on chromosome 1p36.32-p36.22. The locus was designated USH1M. Using a combination of Sanger sequencing and exome sequencing, we identified a novel homozygous 18 base pair inframe deletion in ESPN. Variants of ESPN, encoding the actin-bundling protein espin, have been previously associated with deafness and vestibular areflexia in humans with no apparent visual deficits. Our functional studies in heterologous cells and in mouse organ of Corti explant cultures revealed that the six deleted residues in affected individuals of family PKDF1051 are essential for the actin bundling function of espin demonstrated by ultracentrifugation actin binding and bundling assays. Funduscopic examination of the affected individuals of family PKDF1051 revealed irregular retinal contour, temporal flecks and disc pallor in both eyes. ERG revealed diminished rod photoreceptor function among affected individuals.ConclusionOur study uncovers an additional USH gene, assigns the USH1 phenotype to a variant of ESPN and provides a 12th molecular component to the USH proteome. |
| Databáze: | OpenAIRE |
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