NM_138691.3:c.1265C>T

Variant names:

• chr9-72791926-C-T
• rs868082421
• NM_138691.3:c.1265C>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_138691.3(TMC1):​c.1265C>T​(p.Thr422Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,476 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T422K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TMC1 NM_138691.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.81
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• nonsyndromic genetic hearing loss

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Ambry Genetics
• autosomal recessive nonsyndromic hearing loss 7

  Inheritance: Unknown, AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics
• autosomal dominant nonsyndromic hearing loss 36

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics
• autosomal dominant nonsyndromic hearing loss

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_138691.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 27 curated pathogenic missense variants (we use a threshold of 10). The gene has 8 curated benign missense variants. Gene score misZ: 0.85843 (below the threshold of 3.09). Trascript score misZ: 1.5687 (below the threshold of 3.09). GenCC associations: The gene is linked to nonsyndromic genetic hearing loss, autosomal recessive nonsyndromic hearing loss 7, autosomal dominant nonsyndromic hearing loss 36, hearing loss, autosomal recessive, autosomal dominant nonsyndromic hearing loss.
• BP4: Computational evidence support a benign effect (MetaRNN=0.32340172).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_138691.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TMC1	NM_138691.3	MANE Select	c.1265C>T	p.Thr422Ile	missense	Exon 16 of 24	NP_619636.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TMC1	ENST00000297784.10	TSL:1 MANE Select	c.1265C>T	p.Thr422Ile	missense	Exon 16 of 24	ENSP00000297784.6	Q8TDI8
	TMC1	ENST00000340019.4	TSL:5	c.1265C>T	p.Thr422Ile	missense	Exon 14 of 22	ENSP00000341433.3	Q8TDI8
	TMC1	ENST00000645208.2		c.1265C>T	p.Thr422Ile	missense	Exon 15 of 23	ENSP00000494684.1	Q8TDI8

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461286 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726956

African (AFR) AF: 0.0000598 AC: 2 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44724

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86232

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5394

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111898

Other (OTH) AF: 0.0000166 AC: 1 AN: 60362

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74354

African (AFR) AF: 0.0000241 AC: 1 AN: 41460

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.0000385 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
BayesDel_addAF	Uncertain	0.030	T
BayesDel_noAF	Benign	-0.19
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.24	T
Eigen	Benign	0.093
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.32	T
MetaSVM	Benign	-0.63	T
MutationAssessor	Benign	1.1	L
PhyloP100		4.8
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-2.4	N
REVEL	Benign	0.28
Sift	Benign	0.39	T
Sift4G	Uncertain	0.0080	D
Polyphen		0.097	B
Vest4		0.77
MutPred		0.45		Gain of helix (P = 0.1736)
MVP		0.58
MPC		0.22
ClinPred		0.80	D
GERP RS		5.9
Varity_R		0.34
gMVP		0.49
Mutation Taster		=52/48	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: rs868082421; hg19: chr9-75406842;