Ebermann et al. (2007) studied a German family in which 2 sibs had mild to moderate congenital hearing impairment and retinitis pigmentosa without vestibular dysfunction. Haplotype analysis excluded known Usher syndrome loci, but the affected individuals shared common ... Ebermann et al. (2007) studied a German family in which 2 sibs had mild to moderate congenital hearing impairment and retinitis pigmentosa without vestibular dysfunction. Haplotype analysis excluded known Usher syndrome loci, but the affected individuals shared common haplotypes for the markers of the DFNB31 locus.
Abadie et al. (2012) analyzed the audiologic findings in 100 USH2 patients, including 88 with USH2A (608400) mutations, 10 with GPR98 (602851) mutations, and 2 with WHRN mutations. The median age of diagnosis of hearing loss was 5 ... Abadie et al. (2012) analyzed the audiologic findings in 100 USH2 patients, including 88 with USH2A (608400) mutations, 10 with GPR98 (602851) mutations, and 2 with WHRN mutations. The median age of diagnosis of hearing loss was 5 years (range, 8 months to 31 years), but some patients may have had earlier onset. Usher syndrome was diagnosed at a median age of 34.5 years. Most patients (76%) had moderate hearing loss and most (66%) had a gently down-sloping audiogram. The median pure tone average (PTA) was 59.7 dB. There were no significant differences between patients with USH2A and GPR98 mutations, but the GPR98 cases had a higher proportion of severe hearing loss (40%) compared to USH2A cases (16%). Among all groups, cut-off frequencies were noted at 500-1000 Hz. There was some intrafamilial variability. Overall, Abadie et al. (2012) concluded that it is not possible to predict the mutated gene from audiograms in patients with USH2.
By sequence analysis of a German family with Usher syndrome type IID, Ebermann et al. (2007) identified compound heterozygosity for a nonsense mutation (607928.0002) and a splice site mutation (607928.0003) in the WHRN gene.
In 2 ... By sequence analysis of a German family with Usher syndrome type IID, Ebermann et al. (2007) identified compound heterozygosity for a nonsense mutation (607928.0002) and a splice site mutation (607928.0003) in the WHRN gene. In 2 of 31 French USH2 patients who were not linked to the USH2A locus (608400), Besnard et al. (2012) identified homozygosity and compound heterozygosity for WHRN mutations, respectively (607928.0004; 607928.0005). Besnard et al. (2012) concluded that WHRN mutations account for a very small proportion of mutations causing USH2 (1.3%).