rs876657727

Variant names:

• chr9-72791895-GT-G
• rs876657727
• NM_138691.3:c.1236delT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_138691.3(TMC1):​c.1236delT​(p.Met413CysfsTer4) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,140 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: TMC1 NM_138691.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2 O:1
• Conservation: PhyloP100: 7.99
• Publications: 0 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: AR, Unknown Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• autosomal dominant nonsyndromic hearing loss 36

  Inheritance: AD 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: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-72791895-GT-G is Pathogenic according to our data. Variant chr9-72791895-GT-G is described in ClinVar as Pathogenic. ClinVar VariationId is 228405.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.1236delT	p.Met413CysfsTer4	frameshift	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.1236delT	p.Met413CysfsTer4	frameshift	Exon 16 of 24	ENSP00000297784.6	Q8TDI8
	TMC1	ENST00000340019.4	TSL:5	c.1236delT	p.Met413CysfsTer4	frameshift	Exon 14 of 22	ENSP00000341433.3	Q8TDI8
	TMC1	ENST00000645208.2		c.1236delT	p.Met413CysfsTer4	frameshift	Exon 15 of 23	ENSP00000494684.1	Q8TDI8

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74296

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41420

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: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000843 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	not provided (1)
1	-	-	Rare genetic deafness (1)
-	-	-	Autosomal recessive nonsyndromic hearing loss 7;C1847626:Autosomal dominant nonsyndromic hearing loss 36 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.0
Mutation Taster		=1/199	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs876657727;

hg19: chr9-75406811;