rs1114167416
Variant summary
Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong
The NM_000089.4(COL1A2):c.326G>A(p.Gly109Asp) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G109S) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000089.4 missense, splice_region
Scores
Clinical Significance
Conservation
Publications
- Ehlers-Danlos syndrome, arthrochalasia type, 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Illumina, PanelApp Australia, Labcorp Genetics (formerly Invitae)
- osteogenesis imperfectaInheritance: AD Classification: DEFINITIVE Submitted by: G2P
- osteogenesis imperfecta type 1Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- osteogenesis imperfecta type 2Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen
- osteogenesis imperfecta type 3Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
- osteogenesis imperfecta type 4Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- Ehlers-Danlos syndrome, arthrochalasia typeInheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
- Ehlers-Danlos syndrome, cardiac valvular typeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, ClinGen, PanelApp Australia, Orphanet, G2P
- combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2Inheritance: AD Classification: MODERATE Submitted by: ClinGen, Ambry Genetics
- Ehlers-Danlos/osteogenesis imperfecta syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- high bone mass osteogenesis imperfectaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Genome browser will be placed here
ACMG classification
Our verdict: Pathogenic. The variant received 19 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| COL1A2 | NM_000089.4 | c.326G>A | p.Gly109Asp | missense_variant, splice_region_variant | Exon 8 of 52 | ENST00000297268.11 | NP_000080.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| COL1A2 | ENST00000297268.11 | c.326G>A | p.Gly109Asp | missense_variant, splice_region_variant | Exon 8 of 52 | 1 | NM_000089.4 | ENSP00000297268.6 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 33
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2 Pathogenic:2
This variant is predicted to substitute a glycine residue by an aspartic acid residue in the alpha 2 chain of collagen type I. Glycine substitutions in the triple helical domain of collagen type I cause disruption in the formation of the triple helix in the collagen molecule and are a typical cause of osteogenesis imperfecta. Glycine substitutions that are located close to the N-propeptide cleavage site of collagen type I in addition are associated with an Ehlers-Danlos phenotype (PMID 23692737) This variant has not been observed in the Genome Aggregation Database v.2.1.1, indicating it is very rare. This variant has been reported in the literature as a cause of Osteogenesis Imperfecta/Ehlers-Danlos Syndrome overlap syndrome (PMID 23692737). Prediction tools: (REVEL: 0.96) suggest that the change is detrimental to protein function. -
- -
not provided Pathogenic:1
Occurs in the triple helical domain and replaces a glycine in a canonical Gly-X-Y repeat; missense substitution of a canonical glycine residue is expected to disrupt normal protein folding and function, and this is an established mechanism of disease (Jovanovic et al., 2021); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 25944380, 23692737, 27510842) -
Cardiovascular phenotype Pathogenic:1
The p.G109D variant (also known as c.326G>A), located in coding exon 8 of the COL1A2 gene, results from a G to A substitution at nucleotide position 326. The glycine at codon 109 is replaced by aspartic acid, an amino acid with similar properties. The majority of pathogenic mutations identified to date in COL1A2 have involved the substitution of another amino acid for glycine within the triple-helical domain (Dagleish R. Nucleic Acids Res. 1997 Jan 1;25(1):181-7; Marini JC et al. Hum Mutat. 2007 Mar;28(3):209-21; Bardai G et al. Osteoporos Int 2016 Dec;27(12):3607-3613). This particular glycine substitution has been reported in several patients with osteogenesis imperfecta and Ehlers-Danlos overlap syndrome (Malfait F et al. Orphanet J Rare Dis, 2013 May;8:78; Malmgren B et al. Oral Dis, 2017 Jan;23:42-49). Functional studies in patient fibroblasts suggest that this alteration results in delayed processing of procollagen I into the mature protein (Malfait F et al. Orphanet J Rare Dis, 2013 May;8:78). Internal structural analysis indicates that this alteration disrupts the characteristic G-X-Y motif in the COL1A2 protein and inserts a bulky side chain into a sterically-constrained region (Bella J et al. Science. 1994;266:75-81; Hohenester E et al. Proc. Natl. Acad. Sci. U.S.A. 2008;105:18273-7; Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Osteogenesis imperfecta type I Pathogenic:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at