17-78131644-A-T

Variant names:

• chr17-78131644-A-T
• NM_152468.5:c.56A>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_152468.5(TMC8):​c.56A>T​(p.Glu19Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 34)
• Consequence: TMC8 NM_152468.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.14
• Publications: 0 publications found

Genes affected

TMC8 (HGNC:20474): (transmembrane channel like 8) Epidermodysplasia verruciformis (EV) is an autosomal recessive dermatosis characterized by abnormal susceptibility to human papillomaviruses (HPVs) and a high rate of progression to squamous cell carcinoma on sun-exposed skin. EV is caused by mutations in either of two adjacent genes located on chromosome 17q25.3. Both of these genes encode integral membrane proteins that localize to the endoplasmic reticulum and are predicted to form transmembrane channels. This gene encodes a transmembrane channel-like protein with 8 predicted transmembrane domains and 3 leucine zipper motifs. [provided by RefSeq, Jul 2008]

TMC6 (HGNC:18021): (transmembrane channel like 6) Epidermodysplasia verruciformis (EV) is an autosomal recessive dermatosis characterized by abnormal susceptibility to human papillomaviruses (HPVs) and a high rate of progression to squamous cell carcinoma on sun-exposed skin. EV is caused by mutations in either of two adjacent genes located on chromosome 17q25.3. Both of these genes encode integral membrane proteins that localize to the endoplasmic reticulum and are predicted to form transmembrane channels. This gene encodes a transmembrane channel-like protein with 10 transmembrane domains and 2 leucine zipper motifs. [provided by RefSeq, Jul 2008]

TMC6 Gene-Disease associations (from GenCC):

• epidermodysplasia verruciformis, susceptibility to, 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• epidermodysplasia verruciformis

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMC8	NM_152468.5	c.56A>T	p.Glu19Val	missense_variant	Exon 2 of 16	ENST00000318430.10	NP_689681.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMC8	ENST00000318430.10	c.56A>T	p.Glu19Val	missense_variant	Exon 2 of 16	1	NM_152468.5	ENSP00000325561.4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Epidermodysplasia verruciformis Uncertain:1

Mar 18, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This sequence change replaces glutamic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 19 of the TMC8 protein (p.Glu19Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TMC8-related conditions. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Benign	-0.0085	T
BayesDel_noAF	Benign	-0.25
CADD	Benign	20
DANN	Uncertain	0.99
DEOGEN2	Benign	0.092	.;T
Eigen	Benign	0.15
Eigen_PC	Benign	0.072
FATHMM_MKL	Benign	0.66	D
LIST_S2	Benign	0.46	T;T
M_CAP	Pathogenic	0.50	D
MetaRNN	Uncertain	0.50	T;T
MetaSVM	Uncertain	-0.20	T
MutationAssessor	Uncertain	2.1	.;M
PhyloP100		1.1
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-3.3	.;D
REVEL	Uncertain	0.39
Sift	Uncertain	0.0050	.;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.28
MutPred		0.39		Loss of solvent accessibility (P = 0.0509);Loss of solvent accessibility (P = 0.0509);
MVP		0.68
MPC		2.3
ClinPred		0.95	D
GERP RS		2.9
Varity_R		0.21
gMVP		0.69

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

hg19: chr17-76127725;