rs587779483

Positions:

• chr2-189004046-G-A
• chr2-189004046-G-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The ENST00000304636.9(COL3A1):​c.2726G>A​(p.Gly909Asp) 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. G909V) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL3A1 ENST00000304636.9 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.99

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 13 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in ENST00000304636.9
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-189004046-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 101178.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), COL3A1. . Gene score misZ 4.0879 (greater than the threshold 3.09). Trascript score misZ 4.5995 (greater than threshold 3.09). GenCC has associacion of gene with 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 2-189004046-G-A is Pathogenic according to our data. Variant chr2-189004046-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 938624.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr2-189004046-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL3A1	NM_000090.4	c.2726G>A	p.Gly909Asp	missense_variant	39/51	ENST00000304636.9	NP_000081.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL3A1	ENST00000304636.9	c.2726G>A	p.Gly909Asp	missense_variant	39/51	1	NM_000090.4	ENSP00000304408	P1
COL3A1	ENST00000450867.2	c.2627G>A	p.Gly876Asp	missense_variant	38/50	1		ENSP00000415346

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Ehlers-Danlos syndrome, type 4 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 23, 2019

This sequence change replaces glycine with aspartic acid at codon 909 of the COL3A1 protein (p.Gly909Asp). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and aspartic acid. This variant is not present in population databases (ExAC no frequency). This variant has been observed in an individual affected with Ehlers-Danlos syndrome type IV (PMID: 8680408). This variant is also known as Gly742Asp in the literature. 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). This variant disrupts the p.Gly909 amino acid residue in COL3A1. Other variant(s) that disrupt this residue have been observed in individuals with COL3A1-related conditions (PMID: 10706896), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.91	D
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	4.3	H
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-6.0	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.99
MutPred		1.0		Loss of relative solvent accessibility (P = 0.0306);
MVP		0.99
MPC		0.82
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.87
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: rs587779483; hg19: chr2-189868772; COSMIC: COSV58589949; COSMIC: COSV58589949;