NM_206933.4:c.1001G>C

Variant names:

• chr1-216325447-C-G
• rs758303489
• NM_206933.4:c.1001G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_206933.4(USH2A):​c.1001G>C​(p.Arg334Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,672 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R334G) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: USH2A NM_206933.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.87
• Publications: 0 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-216325448-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 48342.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.878

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_206933.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	USH2A	NM_206933.4	MANE Select	c.1001G>C	p.Arg334Pro	missense	Exon 6 of 72	NP_996816.3
	USH2A	NM_007123.6		c.1001G>C	p.Arg334Pro	missense	Exon 6 of 21	NP_009054.6

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	USH2A	ENST00000307340.8	TSL:1 MANE Select	c.1001G>C	p.Arg334Pro	missense	Exon 6 of 72	ENSP00000305941.3
	USH2A	ENST00000366942.3	TSL:1	c.1001G>C	p.Arg334Pro	missense	Exon 6 of 21	ENSP00000355909.3
	USH2A	ENST00000674083.1		c.1001G>C	p.Arg334Pro	missense	Exon 6 of 73	ENSP00000501296.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461672 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727142

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44690

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39668

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111898

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Apr 16, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant disrupts the p.Arg334 amino acid residue in USH2A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 18452394, 10909849). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This sequence change replaces arginine with proline at codon 334 of the USH2A protein (p.Arg334Pro). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and proline. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with USH2A-related conditions.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.62	D
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.83	T
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Benign	-0.64	T
MutationAssessor	Pathogenic	3.3	M
PhyloP100		5.9
PrimateAI	Benign	0.41	T
PROVEAN	Pathogenic	-4.7	D
REVEL	Uncertain	0.51
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.87
MutPred		0.54		Gain of glycosylation at S333 (P = 0.0914)
MVP		0.95
MPC		0.27
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.93
gMVP		0.92
Mutation Taster		=6/94	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs758303489; hg19: chr1-216498789;