7-94421042-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_000089.4(COL1A2):c.2329C>G(p.Arg777Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,614,006 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R777H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

COL1A2
NM_000089.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.79

Publications

3 publications found

Variant links:

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

COL1A2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM1

In a hotspot region, there are 15 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 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.2329C>G	p.Arg777Gly	missense	Exon 38 of 52	NP_000080.2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
COL1A2	ENST00000297268.11	TSL:1 MANE Select	c.2329C>G	p.Arg777Gly	missense	Exon 38 of 52	ENSP00000297268.6
COL1A2	ENST00000461525.5	TSL:1	n.418C>G		non_coding_transcript_exon	Exon 7 of 7
COL1A2	ENST00000467931.1	TSL:2	n.709C>G		non_coding_transcript_exon	Exon 4 of 4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000795

AC:

AN:

251448

AF XY:

0.00000736

show subpopulations

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461860

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727232

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111992

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74324

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

41446

American (AMR)

AF:

0.00

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10600

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

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

Uncertain:1

Apr 08, 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C65"). This variant has not been reported in the literature in individuals affected with COL1A2-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.002%). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 777 of the COL1A2 protein (p.Arg777Gly).

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.48

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Uncertain

0.0

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.80

Eigen

Uncertain

0.25

Eigen_PC

Uncertain

0.39

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.92

M_CAP

Uncertain

0.15

MetaRNN

Uncertain

0.57

MetaSVM

Uncertain

0.46

MutationAssessor

Uncertain

2.3

PhyloP100

4.8

PrimateAI

Uncertain

0.64

PROVEAN

Pathogenic

-6.1

REVEL

Uncertain

0.49

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0030

Polyphen

0.011

Vest4

0.49

MutPred

0.52

Loss of methylation at R777 (P = 0.0023)

MVP

0.74

MPC

0.27

ClinPred

0.93

GERP RS

5.6

Varity_R

0.81

gMVP

0.90

Mutation Taster

=59/41

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over