rs72648346

Variant names:

• chr17-50194729-CA-C
• rs72648346
• NM_000088.4:c.1452delT

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.1452delT​(p.Gly485AlafsTer56) variant causes a frameshift change. 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:2
• Conservation: PhyloP100: 4.36

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 17-50194729-CA-C is Pathogenic according to our data. Variant chr17-50194729-CA-C is described in ClinVar as [Pathogenic]. Clinvar id is 597595.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50194729-CA-C is described in Lovd as [Pathogenic]. Variant chr17-50194729-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.1452delT	p.Gly485AlafsTer56	frameshift_variant	Exon 21 of 51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.1254delT	p.Gly419AlafsTer56	frameshift_variant	Exon 18 of 48		XP_011522643.1
COL1A1	XM_005257058.5	c.1452delT	p.Gly485AlafsTer56	frameshift_variant	Exon 21 of 49		XP_005257115.2
COL1A1	XM_005257059.5	c.957+1584delT		intron_variant	Intron 14 of 37		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.1452delT	p.Gly485AlafsTer56	frameshift_variant	Exon 21 of 51	1	NM_000088.4	ENSP00000225964.6
COL1A1	ENST00000471344.1	n.396delT		non_coding_transcript_exon_variant	Exon 5 of 8	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Jun 26, 2018

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Osteogenesis imperfecta type I Pathogenic:1

Aug 02, 2021

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: 597595). This premature translational stop signal has been observed in individual(s) with osteogenesis imperfecta (PMID: 11317364). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gly485Alafs*56) 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)		0.020		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: rs72648346; hg19: chr17-48272090;