rs993185407

Positions:

• chr1-216247228-T-C
• chr1-216247228-T-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_206933.4(USH2A):​c.2168-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,538 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: USH2A NM_206933.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 7.32

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.04106605 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.7, offset of 7, new splice context is: attttatctttggggcttAGgtg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-216247228-T-C is Pathogenic according to our data. Variant chr1-216247228-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 556562.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
USH2A	NM_206933.4	c.2168-2A>G		splice_acceptor_variant, intron_variant		ENST00000307340.8	NP_996816.3
USH2A	NM_007123.6	c.2168-2A>G		splice_acceptor_variant, intron_variant			NP_009054.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
USH2A	ENST00000307340.8	c.2168-2A>G		splice_acceptor_variant, intron_variant		1	NM_206933.4	ENSP00000305941.3
USH2A	ENST00000366942.3	c.2168-2A>G		splice_acceptor_variant, intron_variant		1		ENSP00000355909.3
USH2A	ENST00000674083.1	c.2168-2A>G		splice_acceptor_variant, intron_variant				ENSP00000501296.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461538 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727074

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Usher syndrome type 2A;C3151138:Retinitis pigmentosa 39 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 06, 2018	- -

Retinitis pigmentosa 39 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Apr 11, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 19, 2024	- -

Usher syndrome type 2A Pathogenic:2

Pathogenic, no assertion criteria provided	research	National Institute on Deafness and Communication Disorders, National Institutes of Health	Dec 10, 2019	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Apr 11, 2023	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 19, 2023

This sequence change affects an acceptor splice site in intron 12 of the USH2A gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in USH2A are known to be pathogenic (PMID: 10729113, 10909849, 20507924, 25649381). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with clinical features of Usher syndrome (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 556562). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Retinal dystrophy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Blueprint Genetics

Nov 29, 2017

- -

Retinitis pigmentosa Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetics and Molecular Pathology, SA Pathology

Aug 12, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.82		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.77		Position offset: -9
DS_AL_spliceai		0.82		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs993185407; hg19: chr1-216420570;