2-189004357-G-T

Variant names:

• chr2-189004357-G-T
• rs587779542
• NM_000090.4:c.2924G>T

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000090.4(COL3A1):​c.2924G>T​(p.Gly975Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G975S) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.70

Genes affected

COL3A1 (HGNC:2201): (collagen type III alpha 1 chain) This gene encodes the pro-alpha1 chains of type III collagen, a fibrillar collagen that is found in extensible connective tissues such as skin, lung, uterus, intestine and the vascular system, frequently in association with type I collagen. Mutations in this gene are associated with Ehlers-Danlos syndrome type IV, and with aortic and arterial aneurysms. [provided by R. Dalgleish, Feb 2008]

ACMG classification

Verdict is Pathogenic. Variant got 17 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-189004356-G-A is described in Lovd as [Pathogenic].
• PP2: Missense variant in the COL3A1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 495 curated pathogenic missense variants (we use a threshold of 10). The gene has 19 curated benign missense variants. Gene score misZ: 4.0879 (above the threshold of 3.09). Trascript score misZ: 4.5995 (above the threshold of 3.09). GenCC associations: The gene is linked to Ehlers-Danlos syndrome, vascular type, autosomal dominant Ehlers-Danlos syndrome, vascular type, polymicrogyria with or without vascular-type Ehlers-Danlos syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.996
• PP5: Variant 2-189004357-G-T is Pathogenic according to our data. Variant chr2-189004357-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 101246.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-189004357-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL3A1	NM_000090.4	c.2924G>T	p.Gly975Val	missense_variant	Exon 40 of 51	ENST00000304636.9	NP_000081.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL3A1	ENST00000304636.9	c.2924G>T	p.Gly975Val	missense_variant	Exon 40 of 51	1	NM_000090.4	ENSP00000304408.4
COL3A1	ENST00000450867.2	c.2825G>T	p.Gly942Val	missense_variant	Exon 39 of 50	1		ENSP00000415346.2

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

Ehlers-Danlos syndrome, type 4 Pathogenic:3

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Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PP3_Strong+PS4_Supporting+PM6_Supporting+PP4+PP2 -

May 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 975 of the COL3A1 protein (p.Gly975Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with vascular Ehlers-Danlos syndrome (PMID: 18043893, 30474650). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 101246). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt COL3A1 protein function with a positive predictive value of 95%. This variant disrupts the triple helix domain of COL3A1. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236). In COL3A1, variants that affect these glycine residues are significantly enriched in individuals with disease (PMID: 24922459, 25758994) compared to the general population (ExAC). For these reasons, this variant has been classified as Pathogenic. -

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Collagen Diagnostic Laboratory, University of Washington

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.6	H
PrimateAI	Pathogenic	0.79	T
PROVEAN	Pathogenic	-6.4	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.99	D
Vest4		0.99
MutPred		1.0		Gain of ubiquitination at K977 (P = 0.1115);
MVP		0.99
MPC		1.8
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.97
gMVP		1.0

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

LitVar

Other links and lift over

dbSNP: rs587779542; hg19: chr2-189869083;