17-50193023-G-A

Position:

• chr17-50193023-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000088.4(COL1A1):​c.1792C>T​(p.Arg598Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,758 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL1A1 NM_000088.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:7 U:1
• Conservation: PhyloP100: 1.87

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-50193023-G-A is Pathogenic according to our data. Variant chr17-50193023-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 425603.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50193023-G-A is described in Lovd as [Pathogenic]. Variant chr17-50193023-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.1792C>T	p.Arg598Ter	stop_gained	26/51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.1594C>T	p.Arg532Ter	stop_gained	23/48		XP_011522643.1
COL1A1	XM_005257058.5	c.1792C>T	p.Arg598Ter	stop_gained	26/49		XP_005257115.2
COL1A1	XM_005257059.5	c.958-330C>T		intron_variant			XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.1792C>T	p.Arg598Ter	stop_gained	26/51	1	NM_000088.4	ENSP00000225964	P1
COL1A1	ENST00000476387.1	n.141C>T		non_coding_transcript_exon_variant	2/9	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000400 AC: 1 AN: 250274 Hom.: 0 AF XY: 0.00000739 AC XY: 1 AN XY: 135304

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461758 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727172

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

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

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Osteogenesis imperfecta type I Pathogenic:3 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 25, 2023	This sequence change creates a premature translational stop signal (p.Arg598*) in the COL1A1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COL1A1 are known to be pathogenic (PMID: 7942841, 9295084, 9443882). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individual(s) with osteogensis imperfecta (PMID: 24501682, 27044453). ClinVar contains an entry for this variant (Variation ID: 425603). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Department of Medical Sciences, Uppsala University	-	- -
Uncertain significance, flagged submission	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 29, 2024	- -
Pathogenic, no assertion criteria provided	clinical testing	Autoinflammatory diseases unit, CHU de Montpellier	Oct 02, 2024	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 06, 2020	Reported as a potential COL1A1 hotspot variant in individuals with OI (Li et al., 2019; Osteogenesis Imperfecta Variant Database); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 30614853, 27044453, 25944380, 24501682, 15106082, 25525159) -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jun 29, 2023	- -

Osteogenesis imperfecta Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Feb 01, 2020

- -

Osteogenesis imperfecta with normal sclerae, dominant form Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

3billion

Sep 01, 2022

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Stop-gained (nonsense) is predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic without evidence for the classification (ClinVar ID: VCV000425603 / PMID: 15106082). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Uncertain	0.40
Eigen_PC	Benign	0.17
FATHMM_MKL	Benign	0.36	N
MutationTaster	Benign	1.0	A
Vest4		0.87
GERP RS		2.1

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: rs72651614; hg19: chr17-48270384;