17-78131664-A-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_152468.5(TMC8):​c.76A>T​(p.Met26Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000383 in 1,568,298 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M26T) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

TMC8
NM_152468.5 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.21

Publications

0 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.066233516).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TMC8NM_152468.5 linkc.76A>T p.Met26Leu missense_variant Exon 2 of 16 ENST00000318430.10 NP_689681.2 Q8IU68-1A0A024R8N8B3KXZ8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TMC8ENST00000318430.10 linkc.76A>T p.Met26Leu missense_variant Exon 2 of 16 1 NM_152468.5 ENSP00000325561.4 Q8IU68-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152184
Hom.:
0
Cov.:
34
show subpopulations
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000282
AC:
4
AN:
1416114
Hom.:
0
Cov.:
31
AF XY:
0.00000428
AC XY:
3
AN XY:
700324
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32616
American (AMR)
AF:
0.00
AC:
0
AN:
37694
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25302
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37464
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80542
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48290
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5538
European-Non Finnish (NFE)
AF:
0.00000367
AC:
4
AN:
1089988
Other (OTH)
AF:
0.00
AC:
0
AN:
58680
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152184
Hom.:
0
Cov.:
34
AF XY:
0.00
AC XY:
0
AN XY:
74358
show subpopulations
⚠️ 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:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68024
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 = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000283
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Oct 19, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.76A>T (p.M26L) alteration is located in exon 2 (coding exon 1) of the TMC8 gene. This alteration results from a A to T substitution at nucleotide position 76, causing the methionine (M) at amino acid position 26 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.47
CADD
Benign
14
DANN
Benign
0.87
DEOGEN2
Benign
0.0084
.;T
Eigen
Benign
-0.92
Eigen_PC
Benign
-0.81
FATHMM_MKL
Benign
0.54
D
LIST_S2
Benign
0.67
T;T
M_CAP
Benign
0.044
D
MetaRNN
Benign
0.066
T;T
MetaSVM
Benign
-0.87
T
MutationAssessor
Benign
1.7
.;L
PhyloP100
1.2
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
-1.0
.;N
REVEL
Benign
0.074
Sift
Benign
0.65
.;T
Sift4G
Benign
0.14
T;T
Polyphen
0.0
.;B
Vest4
0.24
MutPred
0.37
Loss of MoRF binding (P = 0.0923);Loss of MoRF binding (P = 0.0923);
MVP
0.31
MPC
1.1
ClinPred
0.042
T
GERP RS
-0.65
Varity_R
0.070
gMVP
0.58

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

Publications

Other links and lift over

dbSNP: rs1224236608; hg19: chr17-76127745; API