2-189005381-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 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. 15/21 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 Uncertain significance.

• 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

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 3 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000090.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, COL3A1
• BP4: Computational evidence support a benign effect (MetaRNN=0.21464586).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL3A1	NM_000090.4	c.2963T>C	p.Leu988Pro	missense_variant	41/51	ENST00000304636.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL3A1	ENST00000304636.9	c.2963T>C	p.Leu988Pro	missense_variant	41/51	1	NM_000090.4	P1
COL3A1	ENST00000450867.2	c.2864T>C	p.Leu955Pro	missense_variant	40/50	1

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

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Oct 26, 2020

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
FATHMM_MKL	Benign	0.063	N
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
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.33	T
PROVEAN	Benign	2.6	N
REVEL	Benign	0.27
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.98	D
Vest4		0.28
MutPred		0.29		Loss of stability (P = 0.0674);
MVP		0.62
MPC		2.1
ClinPred		0.17	T
GERP RS		-2.0
Varity_R		0.066
gMVP		0.58

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: rs770525372; hg19: chr2-189870107;