14-75963357-ACC-ACCC

Variant names:

• chr14-75963357-A-AC
• rs1060502826
• NM_003239.5:c.884dupG

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_003239.5(TGFB3):​c.884dupG​(p.Gln296SerfsTer28) variant causes a frameshift 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TGFB3 NM_003239.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.31
• Publications: 0 publications found

Genes affected

TGFB3 (HGNC:11769): (transforming growth factor beta 3) This gene encodes a secreted ligand of the TGF-beta (transforming growth factor-beta) superfamily of proteins. Ligands of this family bind various TGF-beta receptors leading to recruitment and activation of SMAD family transcription factors that regulate gene expression. The encoded preproprotein is proteolytically processed to generate a latency-associated peptide (LAP) and a mature peptide, and is found in either a latent form composed of a mature peptide homodimer, a LAP homodimer, and a latent TGF-beta binding protein, or in an active form consisting solely of the mature peptide homodimer. The mature peptide may also form heterodimers with other TGF-beta family members. This protein is involved in embryogenesis and cell differentiation, and may play a role in wound healing. Mutations in this gene are a cause of aortic aneurysms and dissections, as well as familial arrhythmogenic right ventricular dysplasia 1. [provided by RefSeq, Aug 2016]

IFT43 (HGNC:29669): (intraflagellar transport 43) This gene encodes a subunit of the intraflagellar transport complex A (IFT-A). IFT-A is a multiprotein complex that plays an important role in cilia assembly and maintenance by mediating retrograde ciliary transport. Mutations in this gene are a cause of cranioectodermal dysplasia-3 (CED3), also known as Sensenbrenner syndrome. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Dec 2011]

IFT43 Gene-Disease associations (from GenCC):

• cranioectodermal dysplasia 3

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• short-rib thoracic dysplasia 18 with polydactyly

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• cranioectodermal dysplasia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• ciliopathy

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
• retinitis pigmentosa 81

  Inheritance: AR, Unknown Classification: LIMITED Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 18 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 14-75963357-A-AC is Pathogenic according to our data. Variant chr14-75963357-A-AC is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1764874.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGFB3	NM_003239.5	c.884dupG	p.Gln296SerfsTer28	frameshift_variant	Exon 5 of 7	ENST00000238682.8	NP_003230.1
TGFB3	NM_001329939.2	c.884dupG	p.Gln296SerfsTer28	frameshift_variant	Exon 6 of 8		NP_001316868.1
TGFB3	NM_001329938.2	c.884dupG	p.Gln296SerfsTer48	frameshift_variant	Exon 5 of 5		NP_001316867.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TGFB3	ENST00000238682.8	c.884dupG	p.Gln296SerfsTer28	frameshift_variant	Exon 5 of 7	1	NM_003239.5	ENSP00000238682.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1

Dec 28, 2020

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.884dupG variant, located in coding exon 5 of the TGFB3 gene, results from a duplication of G at nucleotide position 884, causing a translational frameshift with a predicted alternate stop codon (p.Q296Sfs*28). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). While loss of function has not yet been clearly established as a mechanism of disease for TGFB3, alterations resulting in haploinsufficiency have been reported in patients with features consistent with manifestations of Loeys-Dietz syndrome (Schepers D et al. Hum Mutat. 2018;39(5):621-634; Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

not provided Pathogenic:1

Jan 07, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift 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); Has not been previously published as pathogenic or benign to our knowledge -

Rienhoff syndrome Pathogenic:1

May 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Gln296Serfs*28) in the TGFB3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TGFB3 are known to be pathogenic (PMID: 25835445, 26188975). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TGFB3-related conditions. ClinVar contains an entry for this variant (Variation ID: 1764874). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1060502826; hg19: chr14-76429700;