rs72653178

Positions:

• chr17-50188619-C-T

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000088.4(COL1A1):​c.3118G>A​(p.Gly1040Ser) variant causes a missense 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. 11/19 in silico tools predict a damaging 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. G1040A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 7.82

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 17 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-50188618-C-G is described in Lovd as [Likely_pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), COL1A1. . Gene score misZ 3.5319 (greater than the threshold 3.09). Trascript score misZ 5.7733 (greater than threshold 3.09). GenCC has associacion of gene with Caffey disease, Ehlers-Danlos/osteogenesis imperfecta syndrome, combined osteogenesis imperfecta and Ehlers-Danlos syndrome 1, Ehlers-Danlos syndrome, arthrochalasia type, osteogenesis imperfecta type 3, Ehlers-Danlos syndrome, classic type, 1, high bone mass osteogenesis imperfecta, osteogenesis imperfecta type 4, Ehlers-Danlos syndrome, classic type, osteogenesis imperfecta type 2, osteogenesis imperfecta type 1.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 17-50188619-C-T is Pathogenic according to our data. Variant chr17-50188619-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 17330.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50188619-C-T is described in Lovd as [Pathogenic]. Variant chr17-50188619-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.3118G>A	p.Gly1040Ser	missense_variant	43/51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.2920G>A	p.Gly974Ser	missense_variant	40/48		XP_011522643.1
COL1A1	XM_005257058.5	c.2848G>A	p.Gly950Ser	missense_variant	41/49		XP_005257115.2
COL1A1	XM_005257059.5	c.2200G>A	p.Gly734Ser	missense_variant	30/38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.3118G>A	p.Gly1040Ser	missense_variant	43/51	1	NM_000088.4	ENSP00000225964	P1
COL1A1	ENST00000511732.1	n.62G>A		non_coding_transcript_exon_variant	2/2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 21, 2022	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 (HGMD); Not observed in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 9101304, 32234057, 8125479, 27509835, 26177859, 29499418, 18670065, 18798308, 7789952, 30886339, 31715670, 31994750, 32436246, 32123938, 33939306) -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Apr 29, 2020	The COL1A1 c.3118G>A; p.Gly1040Ser variant (rs72653178), also known as p.Gly862Ser, is reported in the literature in several individuals affected with osteogenesis imperfecta (Bardai 2016, Lindahl 2015, Maioli 2019, Mrosk 2018, Obafemi 2008). This variant is reported in ClinVar (Variation ID: 17330), and is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. The glycine at codon 1040 is highly conserved, and computational analyses (SIFT, PolyPhen-2) predict that this variant is deleterious. This codon is located in a triple helix repeat domain, and glycine substitutions are the most frequent pathogenic alterations in this region (Ben Amor 2011). Based on available information, this variant is considered to be pathogenic. References: Bardai G et al. DNA sequence analysis in 598 individuals with a clinical diagnosis of osteogenesis imperfecta: diagnostic yield and mutation spectrum. Osteoporos Int. 2016 Dec;27(12):3607-3613. Ben Amor I et al. Genotype-phenotype correlations in autosomal dominant osteogenesis imperfecta. J Osteoporos. 2011; 2011:540178. Lindahl K et al. Genetic epidemiology, prevalence, and genotype-phenotype correlations in the Swedish population with osteogenesis imperfecta. Eur J Hum Genet. 2015 Aug;23(8):1112. Maioli M et al. Genotype-phenotype correlation study in 364 osteogenesis imperfecta Italian patients. Eur J Hum Genet. 2019 Jul;27(7):1090-1100. Mrosk J et al. Diagnostic strategies and genotype-phenotype correlation in a large Indian cohort of osteogenesis imperfecta. Bone. 2018 May;110:368-377. Obafemi AA et al. Popcorn calcification in osteogenesis imperfecta: incidence, progression, and molecular correlation. Am J Med Genet A. 2008 Nov 1;146A(21):2725-32. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jan 10, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 01, 2012	- -

Osteogenesis imperfecta type III Pathogenic:3

Pathogenic, no assertion criteria provided	literature only	OMIM	Jun 01, 1995	- -
Pathogenic, no assertion criteria provided	clinical testing	Department of Medical Sciences, Uppsala University	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	3billion	May 22, 2022	The variant is not observed in the gnomAD v2.1.1 dataset. 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: 0.93). Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000017330). The variant has been previously reported as de novo in at least two similarly affected unrelated individuals (PMID: 25944380). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

Osteogenesis imperfecta type I Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Jul 02, 2020	Based on the classification scheme VCGS_Germline_v1.3.3, this variant is classified as Pathogenic. Following criteria are met: 0103 - Dominant negative and loss of function are known mechanisms of disease in this gene and are associated with osteogenesis imperfecta. Haploinsufficiency and missense variants that disrupt collagen structure are both known to be pathogenic (PMID: 12362985). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from glycine to serine. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0601 - Variant is located in the well-established functional Gly-X-Y motif. Variants that disrupt the glycine of the Gly-X-Y motif are known to product structural defects in the collagen molecule (PMID: 12362985). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported in many individuals with osteogenesis imperfecta in ClinVar and the literature (PMID: 17078022, 26177859, 27509835). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 17, 2023	This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1040 of the COL1A1 protein (p.Gly1040Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with osteogenesis imperfecta type III and osteogenesis imperfecta type III or IV (PMID: 7789952, 18670065, 18798308, 26177859, 27509835). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 17330). 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. Experimental studies have shown that this missense change affects COL1A1 function (PMID: 7695699, 8218237, 9016532, 17078022, 18670065, 19344236). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.76
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Pathogenic	0.69	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	A
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-5.2	D
REVEL	Pathogenic	0.98
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0030	D
Vest4		1.0
MutPred		0.97		Gain of glycosylation at G1040 (P = 0.0031);
MVP		0.99
MPC		0.56
ClinPred		1.0	D
GERP RS		4.5
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: rs72653178; hg19: chr17-48265980;