9-72821038-A-C

Variant names:

• chr9-72821038-A-C
• rs121908074
• NM_138691.3:c.1960A>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM2 PM5 PP2 BP4

The NM_138691.3(TMC1):​c.1960A>C​(p.Met654Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict 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. M654V) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TMC1 NM_138691.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.40
• Publications: 11 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):

• autosomal recessive nonsyndromic hearing loss 7

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• nonsyndromic genetic hearing loss

  Inheritance: SD, AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen
• autosomal dominant nonsyndromic hearing loss 36

  Inheritance: AD, AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia
• 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.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-72821038-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 4104.
• 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=0.3050804).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMC1	NM_138691.3	c.1960A>C	p.Met654Leu	missense_variant	Exon 20 of 24	ENST00000297784.10	NP_619636.2
TMC1	XM_017014256.2	c.1963A>C	p.Met655Leu	missense_variant	Exon 17 of 21		XP_016869745.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMC1	ENST00000297784.10	c.1960A>C	p.Met654Leu	missense_variant	Exon 20 of 24	1	NM_138691.3	ENSP00000297784.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461884 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33480

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112002

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000197 Hom.: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Benign	-0.0083	T
BayesDel_noAF	Benign	-0.25
CADD	Uncertain	23
DANN	Benign	0.97
DEOGEN2	Benign	0.096	T;T;.;T;.
Eigen	Benign	0.0087
Eigen_PC	Benign	0.21
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	.;.;D;D;D
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.31	T;T;T;T;T
MetaSVM	Benign	-0.75	T
MutationAssessor	Benign	1.1	L;L;.;L;.
PhyloP100		7.4
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.23	N;.;.;N;.
REVEL	Benign	0.18
Sift	Benign	0.031	D;.;.;D;.
Sift4G	Uncertain	0.0050	D;.;.;D;.
Polyphen		0.085	B;B;.;B;.
Vest4		0.54
MutPred		0.61		Gain of catalytic residue at M654 (P = 0.0557);Gain of catalytic residue at M654 (P = 0.0557);.;Gain of catalytic residue at M654 (P = 0.0557);.;
MVP		0.63
MPC		0.16
ClinPred		0.78	D
GERP RS		5.5
Varity_R		0.37
gMVP		0.88
Mutation Taster		=25/75	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs121908074; hg19: chr9-75435954;