chr2-189034161-G-A

Variant names:

• chr2-189034161-G-A
• rs140109751
• NM_000393.5:c.4409C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP6

The NM_000393.5(COL5A2):​c.4409C>T​(p.Ala1470Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,694 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1470T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL5A2 NM_000393.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 8.13
• Publications: 0 publications found

Genes affected

COL5A2 (HGNC:2210): (collagen type V alpha 2 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. Mutations in this gene are associated with Ehlers-Danlos syndrome, types I and II. [provided by RefSeq, Jul 2008]

COL5A2 Gene-Disease associations (from GenCC):

• Ehlers-Danlos syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• Ehlers-Danlos syndrome, classic type

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Ehlers-Danlos syndrome, classic type, 2

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 2-189034161-G-A is Benign according to our data. Variant chr2-189034161-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 264358.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000393.5. 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
	COL5A2	NM_000393.5	MANE Select	c.4409C>T	p.Ala1470Val	missense	Exon 54 of 54	NP_000384.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL5A2	ENST00000374866.9	TSL:1 MANE Select	c.4409C>T	p.Ala1470Val	missense	Exon 54 of 54	ENSP00000364000.3
	COL5A2	ENST00000618828.1	TSL:5	c.3248C>T	p.Ala1083Val	missense	Exon 47 of 47	ENSP00000482184.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461694 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727140

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000299 AC: 1 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44672

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53406

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111924

Other (OTH) AF: 0.00 AC: 0 AN: 60384

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Sep 30, 2015

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A1470V variant (also known as c.4409C>T), located in coding exon 54 of the COL5A2 gene, results from a C to T substitution at nucleotide position 4409. The alanine at codon 1470 is replaced by valine, an amino acid with similar properties. This variant was previously reported in the SNPDatabase as rs140109751. Based on data from the NHLBI Exome Sequencing Project (ESP), the T allele has an overall frequency of approximately 0.01% (1/13006) total alleles studied, having been observed in 0.02% (1/4406) African American alleles. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear.

Ehlers-Danlos syndrome, classic type Benign:1

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Uncertain	0.061	T
BayesDel_noAF	Benign	-0.15
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.33	T
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.85	D
M_CAP	Benign	0.020	T
MetaRNN	Uncertain	0.60	D
MetaSVM	Benign	-0.36	T
MutationAssessor	Benign	2.0	M
PhyloP100		8.1
PrimateAI	Uncertain	0.57	T
PROVEAN	Uncertain	-2.5	N
REVEL	Uncertain	0.39
Sift	Uncertain	0.010	D
Sift4G	Benign	0.16	T
Polyphen		0.63	P
Vest4		0.20
MVP		0.56
MPC		0.26
ClinPred		0.91	D
GERP RS		4.2
Varity_R		0.21
gMVP		0.59
Mutation Taster		=60/40	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs140109751; hg19: chr2-189898887;