9-134815604-G-C

Position:

• chr9-134815604-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_000093.5(COL5A1):​c.4043G>C​(p.Gly1348Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,424 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: COL5A1 NM_000093.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.76

Genes affected

COL5A1 (HGNC:2209): (collagen type V alpha 1 chain) This gene encodes an alpha chain for one of the low abundance fibrillar collagens. Fibrillar collagen molecules are trimers that can be composed of one or more types of alpha chains. Type V collagen is found in tissues containing type I collagen and appears to regulate the assembly of heterotypic fibers composed of both type I and type V collagen. This gene product is closely related to type XI collagen and it is possible that the collagen chains of types V and XI constitute a single collagen type with tissue-specific chain combinations. The encoded procollagen protein occurs commonly as the heterotrimer pro-alpha1(V)-pro-alpha1(V)-pro-alpha2(V). Mutations in this gene are associated with Ehlers-Danlos syndrome, types I and II. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), COL5A1. . Gene score misZ 2.0682 (greater than the threshold 3.09). Trascript score misZ 4.1823 (greater than threshold 3.09). GenCC has associacion of gene with Ehlers-Danlos syndrome, classic type, 1, arterial disorder, Ehlers-Danlos syndrome, classic type.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL5A1	NM_000093.5	c.4043G>C	p.Gly1348Ala	missense_variant	51/66	ENST00000371817.8	NP_000084.3
COL5A1	NM_001278074.1	c.4043G>C	p.Gly1348Ala	missense_variant	51/66		NP_001265003.1
COL5A1	XM_017014266.3	c.4043G>C	p.Gly1348Ala	missense_variant	51/65		XP_016869755.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL5A1	ENST00000371817.8	c.4043G>C	p.Gly1348Ala	missense_variant	51/66	1	NM_000093.5	ENSP00000360882	P4
COL5A1	ENST00000371820.4	c.4043G>C	p.Gly1348Ala	missense_variant	51/66	2		ENSP00000360885	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461424 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726960

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Clinical Genetics Laboratory, Skane University Hospital Lund

May 27, 2022

- -

Ehlers-Danlos syndrome, classic type, 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 07, 2023

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 1348 of the COL5A1 protein (p.Gly1348Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with COL5A1-related conditions. ClinVar contains an entry for this variant (Variation ID: 409100). 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 expected to disrupt COL5A1 protein function with a positive predictive value of 95%. This variant disrupts the triple helix domain of COL5A1. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236), and variants at these glycine residues in COL5A1 are more frequently observed in individuals with disease than in the general population (PMID: 22696272, 23587214). However, the clinical significance of this observation remains uncertain since only a limited number of affected individuals have been described to date. 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	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.70	D;.
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.92	D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	H;H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-5.5	D;.
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.97
MutPred		0.98		Loss of relative solvent accessibility (P = 0.0186);Loss of relative solvent accessibility (P = 0.0186);
MVP		0.98
MPC		0.32
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.89
gMVP		0.99

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: rs1060502252; hg19: chr9-137707450; COSMIC: COSV65665157;