9-134805189-G-A

Position:

• chr9-134805189-G-A

Variant summary

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

The ENST00000371817.8(COL5A1):​c.3233G>A​(p.Gly1078Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. G1078G) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: COL5A1 ENST00000371817.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.84

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.3233G>A	p.Gly1078Glu	missense_variant	41/66	ENST00000371817.8	NP_000084.3
COL5A1	NM_001278074.1	c.3233G>A	p.Gly1078Glu	missense_variant	41/66		NP_001265003.1
COL5A1	XM_017014266.3	c.3233G>A	p.Gly1078Glu	missense_variant	41/65		XP_016869755.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL5A1	ENST00000371817.8	c.3233G>A	p.Gly1078Glu	missense_variant	41/66	1	NM_000093.5	ENSP00000360882.3
COL5A1	ENST00000371820.4	c.3233G>A	p.Gly1078Glu	missense_variant	41/66	2		ENSP00000360885.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 06, 2018

This sequence change replaces glycine with glutamic acid at codon 1078 of the COL5A1 protein (p.Gly1078Glu). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and glutamic acid. 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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 missense 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. This variant has not been reported in the literature in individuals with COL5A1-related disease. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.53
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.68	D;.
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.3	H;H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-6.8	D;.
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	D;.
Vest4		0.93
MutPred		1.0		Gain of solvent accessibility (P = 0.0638);Gain of solvent accessibility (P = 0.0638);
MVP		0.95
MPC		0.70
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.89
gMVP		1.0

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: rs1554803631; hg19: chr9-137697035;