Genetic Variant NM_138691.3:c.884+2dupT (chr9-72772556-G-GT) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5

The NM_138691.3(TMC1):c.884+2dupT variant causes a splice region, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,498 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

TMC1
NM_138691.3 splice_region, intron

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: 7.48

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 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 9-72772556-G-GT is Pathogenic according to our data. Variant chr9-72772556-G-GT is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 229319.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMC1	NM_138691.3 link	c.884+2dupT		splice_region_variant, intron_variant	Intron 13 of 23	ENST00000297784.10	NP_619636.2	Q8TDI8
TMC1	XM_017014256.2 link	c.887+2dupT		splice_region_variant, intron_variant	Intron 10 of 20		XP_016869745.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMC1	ENST00000297784.10 link	c.884+1_884+2insT		splice_donor_variant, intron_variant	Intron 13 of 23	1	NM_138691.3	ENSP00000297784.6		Q8TDI8

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251212

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135750

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad SAS 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:

0.00000274

AC:

AN:

1461498

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727050

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.000111

Hom.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Autosomal recessive nonsyndromic hearing loss 7;C1847626:Autosomal dominant nonsyndromic hearing loss 36

Pathogenic:1

Dec 29, 2023

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:1

Nov 12, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Pathogenic. The c.884+2_884 +3insT variant in TMC1 has not been previously reported in individuals with hear ing loss. This variant was absent from large population studies, though the abil ity of these studies to accurately detect indels may be limited. This variant is located in the 5' splice region. Computational tools suggest an impact to splic ing. However, this information is not predictive enough to determine pathogenici ty. In summary, while there is some suspicion for a pathogenic role, the clinica l significance of the c.884+2_884+3insT variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.23

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.23

Position offset: -1

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