rs1553257761

Variant names:

• chr1-216418513-C-T
• rs1553257761
• NM_206933.4:c.651+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_206933.4(USH2A):​c.651+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000137 in 1,460,560 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: 0.0000014 (0 hom.)
• Consequence: USH2A NM_206933.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 5.82
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• Usher syndrome type 2

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Usher syndrome type 2A

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• retinitis pigmentosa 39

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-216418513-C-T is Pathogenic according to our data. Variant chr1-216418513-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 553412.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
USH2A	NM_206933.4	c.651+1G>A		splice_donor_variant, intron_variant	Intron 3 of 71	ENST00000307340.8	NP_996816.3
USH2A	NM_007123.6	c.651+1G>A		splice_donor_variant, intron_variant	Intron 3 of 20		NP_009054.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
USH2A	ENST00000307340.8	c.651+1G>A		splice_donor_variant, intron_variant	Intron 3 of 71	1	NM_206933.4	ENSP00000305941.3
USH2A	ENST00000366942.3	c.651+1G>A		splice_donor_variant, intron_variant	Intron 3 of 20	1		ENSP00000355909.3
USH2A	ENST00000674083.1	c.651+1G>A		splice_donor_variant, intron_variant	Intron 3 of 72			ENSP00000501296.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460560 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726598

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33404

American (AMR) AF: 0.00 AC: 0 AN: 44656

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39634

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53098

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5742

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111374

Other (OTH) AF: 0.00 AC: 0 AN: 60316

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Usher syndrome Pathogenic:1

Jul 19, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: USH2A c.651+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 250564 control chromosomes. c.651+1G>A has been reported in the literature in compound heterozygous individuals affected with Usher Syndrome (e.g. Stabej_2012, Mansard_2021). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 34948090, 22135276). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Usher syndrome type 2A;C3151138:Retinitis pigmentosa 39 Pathogenic:1

Aug 24, 2017

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:1

Nov 27, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 3 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 individuals with Usher syndrome (PMID: 22135276, 34948090). ClinVar contains an entry for this variant (Variation ID: 553412). 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. -

Retinitis pigmentosa 39 Pathogenic:1

Apr 11, 2023

Genome-Nilou Lab

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Usher syndrome type 2A Pathogenic:1

Apr 11, 2023

Genome-Nilou Lab

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		5.8
GERP RS		5.6
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: 1

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

Other links and lift over

dbSNP: rs1553257761; hg19: chr1-216591855;