chr2-188993438-C-A

Variant names:

• chr2-188993438-C-A
• NM_000090.4:c.1128C>A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000090.4(COL3A1):​c.1128C>A​(p.His376Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.428

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.11379117).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL3A1	NM_000090.4	c.1128C>A	p.His376Gln	missense_variant	Exon 16 of 51	ENST00000304636.9	NP_000081.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL3A1	ENST00000304636.9	c.1128C>A	p.His376Gln	missense_variant	Exon 16 of 51	1	NM_000090.4	ENSP00000304408.4
COL3A1	ENST00000450867.2	c.1050+498C>A		intron_variant	Intron 15 of 49	1		ENSP00000415346.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1404598 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 693218

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.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Ehlers-Danlos syndrome, type 4 Uncertain:1

Feb 04, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 376 of the COL3A1 protein (p.His376Gln). This variant has not been reported in the literature in individuals affected with COL3A1-related conditions. 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.048	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	0.51
DANN	Benign	0.85
DEOGEN2	Benign	0.41	T;.
Eigen	Benign	-1.1
Eigen_PC	Benign	-0.90
FATHMM_MKL	Benign	0.67	D
LIST_S2	Benign	0.55	T;T
M_CAP	Benign	0.070	D
MetaRNN	Benign	0.11	T;T
MetaSVM	Benign	-0.57	T
MutationAssessor	Benign	-0.36	N;N
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-0.44	N;N
REVEL	Uncertain	0.30
Sift	Benign	0.60	T;T
Sift4G	Benign	0.75	T;T
Polyphen		0.0040	B;.
Vest4		0.26
MutPred		0.34		Loss of catalytic residue at H376 (P = 0.183);Loss of catalytic residue at H376 (P = 0.183);
MVP		0.44
MPC		0.63
ClinPred		0.41	T
GERP RS		-1.9
Varity_R		0.068
gMVP		0.38

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-189858164;