17-78117873-G-T

Variant names:

• chr17-78117873-G-T
• rs2613516
• NM_001127198.5:c.1950C>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001127198.5(TMC6):​c.1950C>A​(p.Thr650Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,454,250 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. T650T) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TMC6 NM_001127198.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0930
• Publications: 0 publications found

Genes affected

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: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.49).
• BP7: Synonymous conserved (PhyloP=0.093 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMC6	NM_001127198.5	c.1950C>A	p.Thr650Thr	synonymous_variant	Exon 16 of 20	ENST00000590602.6	NP_001120670.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMC6	ENST00000590602.6	c.1950C>A	p.Thr650Thr	synonymous_variant	Exon 16 of 20	2	NM_001127198.5	ENSP00000465261.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1454250 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 722794

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

African (AFR) AF: 0.00 AC: 0 AN: 33428

American (AMR) AF: 0.00 AC: 0 AN: 43700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25910

East Asian (EAS) AF: 0.00 AC: 0 AN: 39456

South Asian (SAS) AF: 0.00 AC: 0 AN: 85208

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51838

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5750

European-Non Finnish (NFE) AF: 9.02e-7 AC: 1 AN: 1108880

Other (OTH) AF: 0.00 AC: 0 AN: 60080

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.49
CADD	Benign	4.7
DANN	Benign	0.76
PhyloP100		0.093

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs2613516; hg19: chr17-76113954;