Description
The c.5516T>A variant in USH2A is a missense variant predicted to cause substitution of valine to glutamate at amino acid position 1839. The variant was absent from gnomAD v2.1.1 and present in 0.001549% (1/64578) of non-Finnish European chromosomes in gnomAD v3 (PM2_Supporting). Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. This variant has been detected in at least 4 individuals (2 with Usher syndrome and 2 with isolated retinitis pigmentosa) (total of 2.5 PM3 points, PM3_Strong). One individual with Usher syndrome was assumed to be compound heterozygous with a pathogenic c.2299del variant, but phase unknown (VCV000002351.78; PMID: 26927203). The other two individuals had retinitis pigmentosa and were assumed compound heterozygous with pathogenic p.(Cys759Phe) variant (VCV000002356.89; PMID: 26927203; PMID: 34203967). One patient displayed both retinal degradation and sensorineural hearing loss, features highly specific for USH2A (PP4). Patients with this variant may present with either Usher syndrome or with isolated RP. Isolated RP presentations are more common when the variant is seen with missense variants while Usher syndrome is more common when it is found with truncating variants. In summary, the clinical significance of this variant is likely pathogenic. ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss Expert Panel: PM2_Supporting, PM3_Strong, PP4 (VCEP specifications version 2; 10.18.2023).
# | Sample | Method | Observation |
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Origin | Affected | Number tested | Tissue | Purpose | Method | Individuals | Allele frequency | Families | Co-occurrences |
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1 | germline | unknown | not provided | not provided | not provided | | not provided | not provided | not provided | not provided |