rs1060500196

Positions:

• chr2-189010771-A-G
• chr2-189010771-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_000090.4(COL3A1):​c.4135A>G​(p.Met1379Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1379L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.16

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 Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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, 0.779

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL3A1	NM_000090.4	c.4135A>G	p.Met1379Val	missense_variant	50/51	ENST00000304636.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL3A1	ENST00000304636.9	c.4135A>G	p.Met1379Val	missense_variant	50/51	1	NM_000090.4	P1
COL3A1	ENST00000450867.2	c.4036A>G	p.Met1346Val	missense_variant	49/50	1
COL3A1	ENST00000487010.1	n.1514A>G		non_coding_transcript_exon_variant	2/3	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461860 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 727230

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Ehlers-Danlos syndrome, type 4 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 30, 2021	This sequence change replaces methionine with valine at codon 1379 of the COL3A1 protein (p.Met1379Val). The methionine residue is highly conserved and there is a small physicochemical difference between methionine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with COL3A1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	May 16, 2023	This missense variant replaces methionine with valine at codon 1379 of the COL3A1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with COL3A1-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
CADD	Benign	23
DANN	Benign	0.91
DEOGEN2	Uncertain	0.70	D;.
Eigen	Benign	-0.027
Eigen_PC	Benign	0.0043
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Benign	0.081	D
MetaRNN	Pathogenic	0.78	D;D
MetaSVM	Benign	-0.61	T
MutationAssessor	Pathogenic	3.1	M;.
MutationTaster	Benign	1.0	D;N
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-3.0	D;D
REVEL	Uncertain	0.55
Sift	Uncertain	0.0070	D;D
Sift4G	Benign	0.12	T;D
Polyphen		0.49	P;.
Vest4		0.73
MutPred		0.73		Gain of catalytic residue at M1379 (P = 0.087);.;
MVP		0.90
MPC		0.21
ClinPred		0.88	D
GERP RS		4.1
Varity_R		0.89
gMVP		0.57

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: rs1060500196; hg19: chr2-189875497;