rs1060500201

chr2-189010280-A-G

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP2 BP4_Strong

The NM_000090.4(COL3A1):c.3926A>G(p.Asn1309Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000137 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: COL3A1 NM_000090.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -1.20

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 Likely_benign. Variant got -3 ACMG points.

• PP2: Missense variant where missense usually causes diseases, COL3A1
• BP4: Computational evidence support a benign effect (MetaRNN=0.03852868).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL3A1	NM_000090.4	c.3926A>G	p.Asn1309Ser	missense_variant	49/51	ENST00000304636.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL3A1	ENST00000304636.9	c.3926A>G	p.Asn1309Ser	missense_variant	49/51	1	NM_000090.4	P1
COL3A1	ENST00000450867.2	c.3827A>G	p.Asn1276Ser	missense_variant	48/50	1
COL3A1	ENST00000487010.1	n.1023A>G		non_coding_transcript_exon_variant	2/3	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251420 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135882

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000137 AC: 20 AN: 1461844 Hom.: 0 Cov.: 32 AF XY: 0.0000179 AC XY: 13 AN XY: 727222

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000162

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000508 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 17, 2022

The p.N1309S variant (also known as c.3926A>G), located in coding exon 49 of the COL3A1 gene, results from an A to G substitution at nucleotide position 3926. The asparagine at codon 1309 is replaced by serine, an amino acid with highly similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Ehlers-Danlos syndrome, type 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 26, 2021

This sequence change replaces asparagine with serine at codon 1309 of the COL3A1 protein (p.Asn1309Ser). The asparagine residue is weakly conserved and there is a small physicochemical difference between asparagine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with COL3A1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0". The serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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	0.051
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.69
Cadd	Benign	0.0030
Dann	Benign	0.29
DEOGEN2	Benign	0.23	T;.
Eigen	Benign	-2.4
Eigen_PC	Benign	-2.5
FATHMM_MKL	Benign	0.049	N
LIST_S2	Benign	0.81	T;T
M_CAP	Benign	0.022	T
MetaRNN	Benign	0.039	T;T
MetaSVM	Benign	-0.72	T
MutationAssessor	Benign	-0.23	N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.19	N;N
REVEL	Benign	0.21
Sift	Benign	1.0	T;T
Sift4G	Benign	1.0	T;T
Polyphen		0.0	B;.
Vest4		0.14
MutPred		0.40		Loss of catalytic residue at N1309 (P = 0.0166);.;
MVP		0.34
MPC		0.16
ClinPred		0.021	T
GERP RS		-12
Varity_R		0.049
gMVP		0.18

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: rs1060500201; hg19: chr2-189875006;