chr2-189010268-C-G

Position:

• chr2-189010268-C-G

Variant summary

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

The NM_000090.4(COL3A1):​c.3914C>G​(p.Ala1305Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,834 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 (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.91

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]

COL3A1 (HGNC:):

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, 0.778

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL3A1	NM_000090.4	c.3914C>G	p.Ala1305Gly	missense_variant	49/51	ENST00000304636.9	NP_000081.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL3A1	ENST00000304636.9	c.3914C>G	p.Ala1305Gly	missense_variant	49/51	1	NM_000090.4	ENSP00000304408.4
COL3A1	ENST00000450867.2	c.3815C>G	p.Ala1272Gly	missense_variant	48/50	1		ENSP00000415346.2
COL3A1	ENST00000487010.1	n.1011C>G		non_coding_transcript_exon_variant	2/3	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461834 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727222

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Ehlers-Danlos syndrome, type 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 04, 2022

This variant has not been reported in the literature in individuals affected with COL3A1-related conditions. 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. 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 not expected to disrupt COL3A1 protein function. ClinVar contains an entry for this variant (Variation ID: 404295). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 1305 of the COL3A1 protein (p.Ala1305Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Uncertain	0.054	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.48	T;.
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Benign	0.064	D
MetaRNN	Pathogenic	0.78	D;D
MetaSVM	Uncertain	0.16	D
MutationAssessor	Uncertain	2.9	M;.
PrimateAI	Benign	0.47	T
PROVEAN	Uncertain	-2.5	N;D
REVEL	Uncertain	0.53
Sift	Benign	0.090	T;T
Sift4G	Uncertain	0.016	D;D
Polyphen		0.90	P;.
Vest4		0.50
MutPred		0.69		Gain of glycosylation at S1304 (P = 0.0826);.;
MVP		0.73
MPC		0.21
ClinPred		0.93	D
GERP RS		5.9
Varity_R		0.60
gMVP		0.41

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: rs1060500197; hg19: chr2-189874994;