7-94421042-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PM5PP2PP3_Moderate

The NM_000089.4(COL1A2):​c.2329C>T​(p.Arg777Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,860 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. R777H) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

COL1A2
NM_000089.4 missense

Scores

15
3
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.79
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-94421043-G-A is described in Lovd as [Pathogenic].
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), COL1A2. . Gene score misZ 2.1491 (greater than the threshold 3.09). Trascript score misZ 3.5344 (greater than threshold 3.09). GenCC has associacion of gene with Ehlers-Danlos/osteogenesis imperfecta syndrome, Ehlers-Danlos syndrome, cardiac valvular type, ehlers-danlos syndrome, arthrochalasia type, 2, Ehlers-Danlos syndrome, arthrochalasia type, osteogenesis imperfecta type 3, high bone mass osteogenesis imperfecta, combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2, osteogenesis imperfecta type 4, osteogenesis imperfecta type 2, osteogenesis imperfecta type 1.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.88

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
COL1A2NM_000089.4 linkuse as main transcriptc.2329C>T p.Arg777Cys missense_variant 38/52 ENST00000297268.11 NP_000080.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
COL1A2ENST00000297268.11 linkuse as main transcriptc.2329C>T p.Arg777Cys missense_variant 38/521 NM_000089.4 ENSP00000297268 P1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251448
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135900
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461860
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727232
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

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
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpSep 30, 2023This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 777 of the COL1A2 protein (p.Arg777Cys). This variant is present in population databases (rs779108678, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with COL1A2-related conditions. ClinVar contains an entry for this variant (Variation ID: 581514). 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 expected to disrupt COL1A2 protein function. 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
0.58
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Pathogenic
0.16
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.80
D;.
Eigen
Pathogenic
0.82
Eigen_PC
Pathogenic
0.79
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Uncertain
0.25
D
MetaRNN
Pathogenic
0.88
D;D
MetaSVM
Pathogenic
0.96
D
MutationAssessor
Pathogenic
3.2
M;.
MutationTaster
Benign
1.0
D
PrimateAI
Uncertain
0.72
T
PROVEAN
Pathogenic
-6.9
D;.
REVEL
Pathogenic
0.74
Sift
Pathogenic
0.0
D;.
Sift4G
Uncertain
0.043
D;D
Polyphen
1.0
D;.
Vest4
0.72
MutPred
0.71
Loss of methylation at R777 (P = 0.0023);.;
MVP
0.82
MPC
0.29
ClinPred
0.97
D
GERP RS
5.6
Varity_R
0.76
gMVP
0.89

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs779108678; hg19: chr7-94050354; COSMIC: COSV51961827; COSMIC: COSV51961827; API