11-17496805-G-T

Variant names:

• chr11-17496805-G-T
• rs34581703
• NM_153676.4:c.2499C>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_153676.4(USH1C):​c.2499C>A​(p.Ile833Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,822 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars). Synonymous variant affecting the same amino acid position (i.e. I833I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: USH1C NM_153676.4 synonymous
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: -0.917
• Publications: 0 publications found

Genes affected

USH1C (HGNC:12597): (USH1 protein network component harmonin) This gene encodes a scaffold protein that functions in the assembly of Usher protein complexes. The protein contains PDZ domains, a coiled-coil region with a bipartite nuclear localization signal and a PEST degradation sequence. Defects in this gene are the cause of Usher syndrome type 1C and non-syndromic sensorineural deafness autosomal recessive type 18. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2009]

USH1C Gene-Disease associations (from GenCC):

• Usher syndrome type 1

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Usher syndrome type 1C

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, PanelApp Australia
• autosomal recessive nonsyndromic hearing loss 18A

  Inheritance: AR, Unknown Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• nonsyndromic genetic hearing loss

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.43).
• BP7: Synonymous conserved (PhyloP=-0.917 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
USH1C	NM_153676.4	c.2499C>A	p.Ile833Ile	synonymous_variant	Exon 25 of 27	ENST00000005226.12	NP_710142.1
USH1C	NM_005709.4	c.1599C>A	p.Ile533Ile	synonymous_variant	Exon 20 of 21	ENST00000318024.9	NP_005700.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
USH1C	ENST00000005226.12	c.2499C>A	p.Ile833Ile	synonymous_variant	Exon 25 of 27	5	NM_153676.4	ENSP00000005226.7
USH1C	ENST00000318024.9	c.1599C>A	p.Ile533Ile	synonymous_variant	Exon 20 of 21	1	NM_005709.4	ENSP00000317018.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251406 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461822 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727222

⚠️ 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: 33480

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111964

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.029673), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 5

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Usher syndrome type 1C Uncertain:1

Mar 14, 2025

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.43
CADD	Benign	0.95
DANN	Benign	0.73
PhyloP100		-0.92

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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: rs34581703; hg19: chr11-17518352;