rs72651658

chr17-50190861-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.2299G>A(p.Gly767Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,104 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G767D) has been classified as Pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• 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 19 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 3 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 chr17-50190860-C-T is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, COL1A1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 17-50190861-C-T is Pathogenic according to our data. Variant chr17-50190861-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 546096.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50190861-C-T is described in Lovd as [Pathogenic]. Variant chr17-50190861-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL1A1	NM_000088.4	c.2299G>A	p.Gly767Ser	missense_variant	33/51	ENST00000225964.10
COL1A1	XM_011524341.2	c.2101G>A	p.Gly701Ser	missense_variant	30/48
COL1A1	XM_005257058.5	c.2299G>A	p.Gly767Ser	missense_variant	33/49
COL1A1	XM_005257059.5	c.1381G>A	p.Gly461Ser	missense_variant	20/38

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL1A1	ENST00000225964.10	c.2299G>A	p.Gly767Ser	missense_variant	33/51	1	NM_000088.4	P1
COL1A1	ENST00000494334.1	n.64G>A		non_coding_transcript_exon_variant	1/2	2
COL1A1	ENST00000476387.1			downstream_gene_variant		2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152104 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152104 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74304

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Oct 01, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 21, 2021	Reported previously in multiple unrelated individuals with osteogenesis imperfecta in published literature (Forlino et al., 1994; Gentile et al., 2012; Mauri et al., 2016); 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; 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; This variant is associated with the following publications: (PMID: 7881420, 7695699, 22753364, 27484908, 21667357, 27748872, 29499418, 29620724, 30886339, 8218237, 31006186, 31414283, 32770541, 33470886, 32123938, 33939306) -

Osteogenesis imperfecta type I Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jun 11, 2018	This sequence change replaces glycine with serine at codon 767 of the COL1A1 protein (p.Gly767Ser). The glycine residue is highly conserved and there is a small physicochemical difference between glycine and serine. This variant is not present in population databases (ExAC no frequency). This variant (also know as Gly589Ser in the literature) has been observed in individuals affected with osteogenesis imperfecta (OI), including some individuals where it was observed as a de novo variant (PMID: 27484908, 7881420, 22753364). This missense change is located within a functionally conserved triple helix domain of the COL1A1 protein and variants that affect the glycine residue in Gly-Xaa-Yaa repeats of the collagen triple helix are known to disrupt protein folding and stability (PMID: 8218237, 7695699). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein	Apr 11, 2022	ACMG classification criteria: PS4 strong, PM1 moderated, PM2 moderated, PM6 moderated, PP3 supporting -

Osteogenesis imperfecta Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

May 25, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
Cadd	Pathogenic	32
Dann	Uncertain	0.99
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.90	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.95	D
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-5.1	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0020	D
Vest4		1.0
MutPred		1.0		Gain of glycosylation at G767 (P = 0.0029);
MVP		1.0
MPC		1.4
ClinPred		1.0	D
GERP RS		4.7
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: rs72651658; hg19: chr17-48268222; COSMIC: COSV56809727; COSMIC: COSV56809727;