17-50190578-C-T

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000088.4(COL1A1):c.2362G>A(p.Gly788Ser) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G788C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 4.95

Genes affected

COL1A1 (HGNC:2197): (collagen type I alpha 1 chain) This gene encodes the pro-alpha1 chains 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 VIIA, Ehlers-Danlos syndrome Classical type, Caffey Disease and idiopathic osteoporosis. Reciprocal translocations between chromosomes 17 and 22, where this gene and the gene for platelet-derived growth factor beta are located, are associated with a particular type of skin tumor called dermatofibrosarcoma protuberans, resulting from unregulated expression of the growth factor. Two transcripts, resulting from the use of alternate polyadenylation signals, have been identified for this gene. [provided by R. Dalgleish, Feb 2008]

ACMG classification

Verdict is Pathogenic. Variant got 19 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000088.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-50190578-C-A is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, COL1A1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 17-50190578-C-T is Pathogenic according to our data. Variant chr17-50190578-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 447141.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50190578-C-T is described in Lovd as [Pathogenic]. Variant chr17-50190578-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL1A1	NM_000088.4	c.2362G>A	p.Gly788Ser	missense_variant	34/51	ENST00000225964.10
COL1A1	XM_011524341.2	c.2164G>A	p.Gly722Ser	missense_variant	31/48
COL1A1	XM_005257058.5	c.2362G>A	p.Gly788Ser	missense_variant	34/49
COL1A1	XM_005257059.5	c.1444G>A	p.Gly482Ser	missense_variant	21/38

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL1A1	ENST00000225964.10	c.2362G>A	p.Gly788Ser	missense_variant	34/51	1	NM_000088.4	P1
COL1A1	ENST00000494334.1	n.127G>A		non_coding_transcript_exon_variant	2/2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 08, 2021	Occurs in the triple helical domain and replaces the glycine in the 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 (Stenson et al., 2014); Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Reported in ClinVar as pathogenic (ClinVar Variant ID# 447141; Landrum et al., 2016); This variant is associated with the following publications: (PMID: 18412368, 27509835, 29595812, 32123938, 17078022) -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jan 17, 2017	- -

Osteogenesis imperfecta type I Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	3billion	Sep 01, 2022	The variant is not observed in the gnomAD v2.1.1 dataset. It is located in a mutational hot spot and/or well-established functional domain in which established pathogenic variants have been reported (PMID: 17078022, 27519266). Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.98; 3Cnet: 0.99). Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000447141). A different missense change at the same codon (p.Gly788Cys) has been reported to be associated with COL1A1-related disorder (PMID: 15241796). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 01, 2024	This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 788 of the COL1A1 protein (p.Gly788Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with osteogenesis imperfecta (PMID: 17078022, 27509835). ClinVar contains an entry for this variant (Variation ID: 447141). 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 COL1A1 protein function with a positive predictive value of 95%. This variant disrupts the triple helix domain of COL1A1. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236). In COL1A1, variants affecting these glycine residues are significantly enriched in individuals with disease (PMID: 9016532, 17078022) compared to the general population (ExAC). For these reasons, this variant has been classified as Pathogenic. -

Infantile cortical hyperostosis;C0023931:Osteogenesis imperfecta type I;C0029458:Postmenopausal osteoporosis;C0268358:Osteogenesis imperfecta, perinatal lethal;C0268362:Osteogenesis imperfecta type III;C0268363:Osteogenesis imperfecta with normal sclerae, dominant form;C4551623:Ehlers-Danlos syndrome, arthrochalasia type Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

COL1A1-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Oct 30, 2023

The COL1A1 c.2362G>A variant is predicted to result in the amino acid substitution p.Gly788Ser. The p.Gly788 amino acid is located in the conserved Gly-Xaa-Yaa triple helical domain where substitutions of a glycine are usually pathogenic (Marini et al. 2007. PubMed ID: 17078022). In addition, this variant was reported in multiple individuals with osteogenesis imperfecta (see examples: Table S1, Bardai et al. 2016. PubMed ID: 27509835; Table 1, Chandler et al. 2018. PubMed ID: 29595812; Table 1, Zhytnik et al. 2020. PubMed ID: 32166892; Table 1, Zhang et al. 2021. PubMed ID: 33942288). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
Cadd	Pathogenic	28
Dann	Uncertain	0.99
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.95	D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-5.4	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.041	D
Vest4		0.99
MutPred		0.98		Gain of phosphorylation at G788 (P = 0.0028);
MVP		0.99
MPC		0.56
ClinPred		1.0	D
GERP RS		4.8
gMVP		1.0

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

Other links and lift over

dbSNP: rs67879854; hg19: chr17-48267939; COSMIC: COSV56802231; COSMIC: COSV56802231;