2-188999568-G-T

Variant names:

• chr2-188999568-G-T
• rs541557925
• NM_000090.4:c.2220G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_000090.4(COL3A1):​c.2220G>T​(p.Lys740Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,264 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. K740K) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.429
• 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)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 15 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 11 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.816

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000090.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL3A1	NM_000090.4	MANE Select	c.2220G>T	p.Lys740Asn	missense	Exon 31 of 51	NP_000081.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL3A1	ENST00000304636.9	TSL:1 MANE Select	c.2220G>T	p.Lys740Asn	missense	Exon 31 of 51	ENSP00000304408.4
	COL3A1	ENST00000450867.2	TSL:1	c.2121G>T	p.Lys707Asn	missense	Exon 30 of 50	ENSP00000415346.2
	COL3A1	ENST00000713745.1		c.2067G>T	p.Lys689Asn	missense	Exon 29 of 49	ENSP00000519049.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152146 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249330 AF XY: 0.00

Gnomad AFR exome AF: 0.0000619

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152264 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74456

African (AFR) AF: 0.0000241 AC: 1 AN: 41548

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3464

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2112

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Uncertain	0.086	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D
Eigen	Benign	0.10
Eigen_PC	Benign	-0.0052
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.84	T
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.82	D
MetaSVM	Pathogenic	0.80	D
MutationAssessor	Uncertain	2.2	M
PhyloP100		0.43
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.8	D
REVEL	Uncertain	0.63
Sift	Uncertain	0.019	D
Sift4G	Uncertain	0.025	D
Polyphen		1.0	D
Vest4		0.70
MutPred		0.52		Loss of glycosylation at K740 (P = 0.0049)
MVP		0.86
MPC		0.74
ClinPred		0.99	D
GERP RS		-0.26
Varity_R		0.32
gMVP		0.95
Mutation Taster		=55/45	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs541557925; hg19: chr2-189864294;