2-189005381-T-C

Variant names:

• chr2-189005381-T-C
• rs770525372
• NM_000090.4:c.2963T>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_000090.4(COL3A1):​c.2963T>C​(p.Leu988Pro) 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. 16/22 in silico tools predict a benign 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. L988H) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.519
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• autosomal dominant Ehlers-Danlos syndrome, vascular type

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Genomics England PanelApp
• Ehlers-Danlos syndrome, vascular type

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• polymicrogyria with or without vascular-type Ehlers-Danlos syndrome

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)

ENSG00000295704 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_000090.4
• 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, polymicrogyria with or without vascular-type Ehlers-Danlos syndrome, autosomal dominant Ehlers-Danlos syndrome, vascular type.
• BP4: Computational evidence support a benign effect (MetaRNN=0.21464586).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL3A1	NM_000090.4	c.2963T>C	p.Leu988Pro	missense_variant	Exon 41 of 51	ENST00000304636.9	NP_000081.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL3A1	ENST00000304636.9	c.2963T>C	p.Leu988Pro	missense_variant	Exon 41 of 51	1	NM_000090.4	ENSP00000304408.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

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

Oct 26, 2020

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868].

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.065
BayesDel_addAF	Benign	-0.049	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	5.9
DANN	Benign	0.83
DEOGEN2	Benign	0.39	T
Eigen	Benign	-0.85
Eigen_PC	Benign	-0.91
LIST_S2	Benign	0.78	T
M_CAP	Uncertain	0.20	D
MetaRNN	Benign	0.21	T
MetaSVM	Benign	-0.34	T
MutationAssessor	Benign	0.30	N
PhyloP100		-0.52
PrimateAI	Benign	0.33	T
PROVEAN	Benign	2.6	N
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Vest4		0.28
ClinPred		0.17	T
GERP RS		-2.0
Varity_R		0.066
gMVP		0.58
Mutation Taster		=98/2	polymorphism

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

Other links and lift over

dbSNP: rs770525372; hg19: chr2-189870107;