rs72651634

Variant names:

• chr17-50191997-CA-C
• rs72651634
• NM_000088.4:c.2010delT

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.2010delT​(p.Gly671AlafsTer95) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL1A1 NM_000088.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: -0.490

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 17-50191997-CA-C is Pathogenic according to our data. Variant chr17-50191997-CA-C is described in ClinVar as [Pathogenic]. Clinvar id is 497350.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50191997-CA-C is described in Lovd as [Pathogenic]. Variant chr17-50191997-CA-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.2010delT	p.Gly671AlafsTer95	frameshift_variant	Exon 30 of 51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.1812delT	p.Gly605AlafsTer95	frameshift_variant	Exon 27 of 48		XP_011522643.1
COL1A1	XM_005257058.5	c.2010delT	p.Gly671AlafsTer95	frameshift_variant	Exon 30 of 49		XP_005257115.2
COL1A1	XM_005257059.5	c.1092delT	p.Gly365AlafsTer95	frameshift_variant	Exon 17 of 38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.2010delT	p.Gly671AlafsTer95	frameshift_variant	Exon 30 of 51	1	NM_000088.4	ENSP00000225964.6
COL1A1	ENST00000476387.1	n.359delT		non_coding_transcript_exon_variant	Exon 6 of 9	2
COL1A1	ENST00000504289.1	n.442delT		non_coding_transcript_exon_variant	Exon 1 of 2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 44

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Mar 22, 2022

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_supporting, PS4_moderate, PVS1 -

Sep 30, 2016

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

COL1A1-related disorder Pathogenic:1

Jun 02, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The COL1A1 c.2010delT variant is predicted to result in a frameshift and premature protein termination (p.Gly671Alafs*95). This variant has been reported to be causative for osteogenesis imperfecta (OI) (Table 1, Family Hu7, Reported as P492fsX587, Ward et al. 2001. PubMed ID: 11317364; Patient 3, Balasubramanian et al. 2016. PubMed ID: 26863094; Supplementary Table 2, Bertoli-Avella et al. 2020. PubMed ID: 32860008; Table 3, Patient ID 31, Higuchi et al. 2021. PubMed ID: 33939306). This variant was also reported, along with a COL5A1 variant, in a family with a compound phenotype of OI and Ehlers-Danlos syndrome (Lin et al. 2019. PubMed ID: 31239369). Of note, two family members had both variants and the compound phenotypes, while two other members only had the COL1A1 variant and only the OI phenotype. This variant has not been reported in a large population database, indicating this variant is rare. Frameshift variants in COL1A1 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Osteogenesis imperfecta, perinatal lethal Pathogenic:1

-

Centogene AG - the Rare Disease Company

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Osteogenesis imperfecta type I Pathogenic:1

Feb 16, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 497350). This premature translational stop signal has been observed in individuals with osteogenesis imperfecta type I (PMID: 11317364; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gly671Alafs*95) 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). -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs72651634; hg19: chr17-48269358;