NM_138691.3:c.1333C>T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_138691.3(TMC1):c.1333C>T(p.Arg445Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000607 in 1,613,856 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000061 ( 0 hom. )

Consequence

TMC1
NM_138691.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7U:2B:1

Conservation

PhyloP100: 3.98

Variant links:

Genes affected

TMC1 (HGNC:16513): (transmembrane channel like 1) This gene is considered a member of a gene family predicted to encode transmembrane proteins. The specific function of this gene is unknown; however, it is known to be required for normal function of cochlear hair cells. Mutations in this gene have been associated with progressive postlingual hearing loss and profound prelingual deafness. [provided by RefSeq, Jul 2008]

TMC1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.875

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMC1	NM_138691.3 link	c.1333C>T	p.Arg445Cys	missense_variant	Exon 16 of 24	ENST00000297784.10	NP_619636.2	Q8TDI8
TMC1	XM_017014256.2 link	c.1336C>T	p.Arg446Cys	missense_variant	Exon 13 of 21		XP_016869745.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMC1	ENST00000297784.10 link	c.1333C>T	p.Arg445Cys	missense_variant	Exon 16 of 24	1	NM_138691.3	ENSP00000297784.6		Q8TDI8

Frequencies

GnomAD3 genomes

AF:

0.0000592

AC:

AN:

152102

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000716

AC:

AN:

251326

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135806

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000114

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000609

AC:

AN:

1461754

Hom.:

Cov.:

AF XY:

0.0000454

AC XY:

AN XY:

727184

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.0000580

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000701

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000592

AC:

AN:

152102

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74296

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000882

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000423

Hom.:

Bravo

AF:

0.0000604

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:7Uncertain:2Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:2Uncertain:2

Dec 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 445 of the TMC1 protein (p.Arg445Cys). This variant is present in population databases (rs372710475, gnomAD 0.02%). This missense change has been observed in individuals with autosomal recessive deafness (PMID: 19187973, 24416283). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 179070). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt TMC1 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Feb 08, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26186295, 26226225, 24933710, 28862181, 31980526, 35640668, 34758253, 33205915, 24416283, 19187973, 34523024, 36597107) -

May 31, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 20, 2019

Athena Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The best available variant frequency is uninformative because it is below the disease allele frequency. Found in at least one symptomatic patient. Predicted to have a damaging effect on the protein. Strong co-segregation with disease in affected and unaffected individuals, but from a single family. -

Autosomal dominant nonsyndromic hearing loss 36

Pathogenic:1Benign:1

Genomics England Pilot Project, Genomics England

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

TMC1-related disorder

Pathogenic:1

Dec 14, 2023

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The TMC1 c.1333C>T variant is predicted to result in the amino acid substitution p.Arg445Cys. This variant was reported in the homozygous or compound heterozygous state in multiple patients with hearing loss (Sirmaci et al. 2009. PubMed ID: 19187973; Ganapathy et al. 2014. PubMed ID: 24416283; Nishio et al. 2022. PubMed ID: 34523024). This variant is reported in 0.016% of alleles in individuals of East Asian descent in gnomAD. This variant is interpreted as pathogenic. -

Nonsyndromic genetic hearing loss

Pathogenic:1

Jun 20, 2023

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TMC1 c.1333C>T (p.Arg445Cys) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 7.2e-05 in 251326 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in TMC1 causing Nonsyndromic Hearing Loss And Deafness, Type 7 (7.2e-05 vs 0.0011), allowing no conclusion about variant significance. c.1333C>T has been reported in the literature as a biallelic genotype in multiple individuals affected with Nonsyndromic Hearing Loss And Deafness (e.g. Sirmaci_2009, Ganapathy_2014, Nishio_2022). These data indicate that the variant is very likely to 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: 24416283, 34523024, 30303587, 19187973). Five ClinVar submitters have assessed this variant since 2014: one classified the variant as likely benign, three as uncertain significance, and one as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Hearing loss, autosomal recessive

Pathogenic:1

University of Washington Center for Mendelian Genomics, University of Washington

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Rare genetic deafness

Pathogenic:1

Jul 09, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Arg445Cys variant in TMC1 has been reported in 5 families with hearing loss (Sirmaci 2009, Ganapathy 2014, LMM unpublished data). In one family, the varian t is homozygous in 3 siblings with nonsyndromic autosomal recessive sensorineura l hearing loss and heterozygous in 4 unaffected relatives (Sirmaci 2009). In an other family, it is homozygous in two affected individuals (Ganapathy 2014). Th is variant has been identified in 0.01% (1/8600) of European American chromosome s by the NHLBI Exome sequencing project (http://evs.gs.washington.edu/EVS/). Alt hough this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. In addition, comput ational prediction tools and conservation analyses suggest that the Arg445Cys va riant may impact the protein, though this information is not predictive enough t o determine pathogenicity. In summary, this variant is likely to be pathogenic, though additional studies are required to fully establish its clinical significa nce. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Uncertain

0.16

BayesDel_noAF

Pathogenic

0.26

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.87

D;D;.;D;.

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.95

.;.;D;D;D

M_CAP

Uncertain

0.11

MetaRNN

Pathogenic

0.87

D;D;D;D;D

MetaSVM

Uncertain

0.089

MutationAssessor

Pathogenic

3.1

M;M;.;M;.

PrimateAI

Pathogenic

0.83

PROVEAN

Pathogenic

-8.0

D;.;.;D;.

REVEL

Pathogenic

0.66

Sift

Pathogenic

0.0

D;.;.;D;.

Sift4G

Pathogenic

0.0

D;.;.;D;.

Polyphen

1.0

D;D;.;D;.

Vest4

0.97

MVP

0.83

MPC

0.73

ClinPred

0.86

GERP RS

5.9

Varity_R

0.80

gMVP

0.96

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over