rs397518013

Positions:

• chr1-216199889-AAT-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_206933.4(USH2A):​c.3547_3548del​(p.Ile1183PhefsTer19) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,836 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: USH2A NM_206933.4 frameshift
• Clinical Significance: Likely pathogenic reviewed by expert panel P:6 U:1
• Conservation: PhyloP100: 2.09

Genes affected

USH2A (HGNC:12601): (usherin) This gene encodes a protein that contains laminin EGF motifs, a pentaxin domain, and many fibronectin type III motifs. The protein is found in the basement membrane, and may be important in development and homeostasis of the inner ear and retina. Mutations within this gene have been associated with Usher syndrome type IIa and retinitis pigmentosa. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2008]

USH2A-AS1 (HGNC:40606): (USH2A antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-216199889-AAT-A is Pathogenic according to our data. Variant chr1-216199889-AAT-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 48503.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
USH2A	NM_206933.4	c.3547_3548del	p.Ile1183PhefsTer19	frameshift_variant	17/72	ENST00000307340.8	NP_996816.3
USH2A-AS1	XR_922596.4	n.691+3969_691+3970del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
USH2A	ENST00000307340.8	c.3547_3548del	p.Ile1183PhefsTer19	frameshift_variant	17/72	1	NM_206933.4	ENSP00000305941	P1
USH2A	ENST00000366942.3	c.3547_3548del	p.Ile1183PhefsTer19	frameshift_variant	17/21	1		ENSP00000355909
USH2A-AS1	ENST00000420867.1	n.362+3969_362+3970del		intron_variant, non_coding_transcript_variant		3
USH2A	ENST00000674083.1	c.3547_3548del	p.Ile1183PhefsTer19	frameshift_variant	17/73			ENSP00000501296

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251000 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135638

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461836 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727230

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:6 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Retinitis pigmentosa 39 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 16, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 18, 2016	- -

Usher syndrome Pathogenic:1

Likely pathogenic, reviewed by expert panel

curation

ClinGen Hearing Loss Variant Curation Expert Panel

Nov 22, 2022

The p.Ile1183fs variant in USH2A introduces a premature stop codon in biologically-relevant-exon 17/72 that is predicted to lead to a truncated or absent protein in a gene in which loss-of-function is an established disease mechanism (PVS1; PMIDs: 9624053, 25211151, 20497194). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00088% (1/113352 alleles) in the European (non-Finnish) population, which is lower than the ClinGen Hearing Loss VCEP threshold (<0.007%) for PM2_Supporting, meeting this criterion (PM2_Supporting). One proband with autosomal recessive retinitis pigmentosa was identified to be carrying the p.Ile1183fs variant with no variant reported in trans (PMID: 35266249). This variant was re-reviewed on 11/22/2022 and because no additional evidence is available, professional judgment was used to retain this variant as likely pathogenic for autosomal recessive Usher Syndrome based on the ACMG/AMP criteria applied as specified by the ClinGen Hearing Loss VCEP: PVS1, PM2_P (ClinGen Hearing Loss VCEP specifications version 2; 11/22/2022). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 17, 2023

This sequence change creates a premature translational stop signal (p.Ile1183Phefs*19) in the USH2A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in USH2A are known to be pathogenic (PMID: 10729113, 10909849, 20507924, 25649381). This variant is present in population databases (rs397518013, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with USH2A-related conditions. ClinVar contains an entry for this variant (Variation ID: 48503). For these reasons, this variant has been classified as Pathogenic. -

Rare genetic deafness Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Mar 31, 2011

The Ile1183fs variant in USH2A has not been reported in the literature nor previ ously identified by our laboratory. The Ile1183fs variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 1183 and leads to a premature stop codon 18 codons downstream. This alteration i s then predicted to lead to a truncated or absent protein. In summary, this vari ant meets our criteria to be classified as pathogenic. -

Usher syndrome type 2A Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Counsyl

Aug 18, 2016

- -

USH2A-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

The USH2A c.3547_3548delAT (p.Ile1183PhefsTer19) variant results in a frameshift and is predicted to result in premature termination of the protein. A literature search was performed for the gene, cDNA change, and amino acid change. No publications were found based on this search. The variant is reported at a frequency of 0.00206 in the European American population of the Exome Sequencing Project. Based on the variant frequency, disease prevalence, disease penetrance, and inheritance mode, this variant could not be ruled out of causing disease. Due to the potential impact of frameshift variants and the lack of clarifying evidence, this variant is classified as a variant of unknown significance but suspicious for pathogenicity for USH2A-related disorders. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs397518013; hg19: chr1-216373231;