NM_001365276.2:c.2116_2117dupGT

Variant names:

• chr6-32095735-T-TAC
• rs144556766
• NM_001365276.2:c.2116_2117dupGT

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001365276.2(TNXB):​c.2116_2117dupGT​(p.Glu707fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,596 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: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TNXB NM_001365276.2 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 1.80
• Publications: 3 publications found

Genes affected

TNXB (HGNC:11976): (tenascin XB) This gene encodes a member of the tenascin family of extracellular matrix glycoproteins. The tenascins have anti-adhesive effects, as opposed to fibronectin which is adhesive. This protein is thought to function in matrix maturation during wound healing, and its deficiency has been associated with the connective tissue disorder Ehlers-Danlos syndrome. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. It is one of four genes in this cluster which have been duplicated. The duplicated copy of this gene is incomplete and is a pseudogene which is transcribed but does not encode a protein. The structure of this gene is unusual in that it overlaps the CREBL1 and CYP21A2 genes at its 5' and 3' ends, respectively. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

TNXB Gene-Disease associations (from GenCC):

• Ehlers-Danlos syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• Ehlers-Danlos syndrome due to tenascin-X deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Illumina, PanelApp Australia, Orphanet
• familial vesicoureteral reflux

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• vesicoureteral reflux 8

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 12 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 6-32095735-T-TAC is Pathogenic according to our data. Variant chr6-32095735-T-TAC is described in ClinVar as Pathogenic. ClinVar VariationId is 8551.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNXB	NM_001365276.2	c.2116_2117dupGT	p.Glu707fs	frameshift_variant	Exon 3 of 44	ENST00000644971.2	NP_001352205.1
TNXB	NM_001428335.1	c.2116_2117dupGT	p.Glu707fs	frameshift_variant	Exon 3 of 45		NP_001415264.1
TNXB	NM_019105.8	c.2116_2117dupGT	p.Glu707fs	frameshift_variant	Exon 3 of 44		NP_061978.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNXB	ENST00000644971.2	c.2116_2117dupGT	p.Glu707fs	frameshift_variant	Exon 3 of 44		NM_001365276.2	ENSP00000496448.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461596 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727098

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53378

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111796

Other (OTH) AF: 0.00 AC: 0 AN: 60370

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Ehlers-Danlos syndrome due to tenascin-X deficiency Pathogenic:1

Oct 18, 2001

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided Pathogenic:1

Apr 17, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 31589614, 11642233) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.8
Mutation Taster		=2/198	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs144556766; hg19: chr6-32063512;