7-94408810-C-T

Variant names:

• chr7-94408810-C-T
• rs1554395967
• NM_000089.4:c.779C>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000089.4(COL1A2):​c.779C>T​(p.Ala260Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A260T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL1A2 NM_000089.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.91
• Publications: 0 publications found

Genes affected

COL1A2 (HGNC:2198): (collagen type I alpha 2 chain) This gene encodes the pro-alpha2 chain of type I collagen whose triple helix comprises two alpha1 chains and one alpha2 chain. Type I is a fibril-forming collagen found in most connective tissues and is abundant in bone, cornea, dermis and tendon. Mutations in this gene are associated with osteogenesis imperfecta types I-IV, Ehlers-Danlos syndrome type VIIB, recessive Ehlers-Danlos syndrome Classical type, idiopathic osteoporosis, and atypical Marfan syndrome. Symptoms associated with mutations in this gene, however, tend to be less severe than mutations in the gene for the alpha1 chain of type I collagen (COL1A1) reflecting the different role of alpha2 chains in matrix integrity. Three transcripts, resulting from the use of alternate polyadenylation signals, have been identified for this gene. [provided by R. Dalgleish, Feb 2008]

COL1A2 Gene-Disease associations (from GenCC):

• Ehlers-Danlos syndrome, arthrochalasia type, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Illumina, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• osteogenesis imperfecta

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• osteogenesis imperfecta type 1

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• osteogenesis imperfecta type 2

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen
• osteogenesis imperfecta type 3

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• osteogenesis imperfecta type 4

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

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• Ehlers-Danlos syndrome, cardiac valvular type

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, ClinGen, PanelApp Australia, Orphanet, G2P
• combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen, Ambry Genetics
• Ehlers-Danlos/osteogenesis imperfecta syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• high bone mass osteogenesis imperfecta

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 18 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000089.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the COL1A2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 437 curated pathogenic missense variants (we use a threshold of 10). The gene has 17 curated benign missense variants. Gene score misZ: 2.1491 (below the threshold of 3.09). Trascript score misZ: 3.5344 (above the threshold of 3.09). GenCC associations: The gene is linked to osteogenesis imperfecta, osteogenesis imperfecta type 1, osteogenesis imperfecta type 4, Ehlers-Danlos syndrome, cardiac valvular type, Ehlers-Danlos syndrome, arthrochalasia type, 2, combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2, Ehlers-Danlos syndrome, arthrochalasia type, osteogenesis imperfecta type 3, osteogenesis imperfecta type 2, high bone mass osteogenesis imperfecta, Ehlers-Danlos/osteogenesis imperfecta syndrome.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000089.4. 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
	COL1A2	NM_000089.4	MANE Select	c.779C>T	p.Ala260Val	missense	Exon 16 of 52	NP_000080.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL1A2	ENST00000297268.11	TSL:1 MANE Select	c.779C>T	p.Ala260Val	missense	Exon 16 of 52	ENSP00000297268.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Osteogenesis imperfecta type I;C0268335:Ehlers-Danlos syndrome, classic type, 1 Uncertain:1

Dec 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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 not expected to disrupt COL1A2 protein function. ClinVar contains an entry for this variant (Variation ID: 547237). This variant has not been reported in the literature in individuals affected with COL1A2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 260 of the COL1A2 protein (p.Ala260Val).

Connective tissue disorder Uncertain:1

Nov 01, 2016

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.030
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.66	D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.93	D
M_CAP	Benign	0.076	D
MetaRNN	Uncertain	0.57	D
MetaSVM	Uncertain	0.59	D
MutationAssessor	Benign	1.3	L
PhyloP100		4.9
PrimateAI	Uncertain	0.52	T
PROVEAN	Uncertain	-2.6	D
REVEL	Uncertain	0.50
Sift	Benign	0.053	T
Sift4G	Benign	0.22	T
Polyphen		0.84	P
Vest4		0.53
MutPred		0.45		Gain of catalytic residue at A260 (P = 0.1065)
MVP		0.64
MPC		0.26
ClinPred		0.94	D
GERP RS		5.7
Varity_R		0.19
gMVP		0.61
Mutation Taster		=81/19	polymorphism

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

Other links and lift over

dbSNP: rs1554395967; hg19: chr7-94038122;