chr7-94408343-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate

The NM_000089.4(COL1A2):​c.701G>T​(p.Arg234Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,892 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R234C) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

COL1A2
NM_000089.4 missense

Scores

10
8
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.78

Publications

4 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 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.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.909

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL1A2NM_000089.4 linkc.701G>T p.Arg234Leu missense_variant Exon 15 of 52 ENST00000297268.11 NP_000080.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL1A2ENST00000297268.11 linkc.701G>T p.Arg234Leu missense_variant Exon 15 of 52 1 NM_000089.4 ENSP00000297268.6

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251464
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:
0.000109
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461892
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000824
AC:
1

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
Jan 13, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 234 of the COL1A2 protein (p.Arg234Leu). This variant is present in population databases (rs376341785, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with COL1A2-related conditions. Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt COL1A2 protein function with a positive predictive value of 95%. 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
0.67
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.41
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.79
D;.
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.96
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
D;D
M_CAP
Uncertain
0.28
D
MetaRNN
Pathogenic
0.91
D;D
MetaSVM
Pathogenic
0.95
D
MutationAssessor
Uncertain
2.4
M;.
PhyloP100
7.8
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-5.1
D;.
REVEL
Pathogenic
0.82
Sift
Uncertain
0.0010
D;.
Sift4G
Uncertain
0.021
D;D
Polyphen
1.0
D;.
Vest4
0.75
MutPred
0.78
Loss of methylation at R234 (P = 0.004);.;
MVP
0.93
MPC
0.32
ClinPred
0.99
D
GERP RS
5.8
Varity_R
0.65
gMVP
0.79
Mutation Taster
=26/74
disease causing

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

Publications

Other links and lift over

dbSNP: rs376341785; hg19: chr7-94037655; API