rs1555572456

Positions:

• chr17-50189417-GGGCCAG-GCGCCA

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1 PM2 PP2 PP5_Moderate

The NM_000088.4(COL1A1):​c.2783_2788delCTGGCCinsTGGCG​(p.Pro928fs) variant causes a frameshift, missense change involving the alteration of a 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, missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.87

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 13 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
• 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). The gene has 368 curated pathogenic missense variants (we use a threshold of 10). The gene has 98 curated benign missense variants. GenCC has associacion of the 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.
• PP5: Variant 17-50189418-GGCCAG-CGCCA is Pathogenic according to our data. Variant chr17-50189418-GGCCAG-CGCCA is described in ClinVar as [Pathogenic]. Clinvar id is 456757.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.2783_2788delCTGGCCinsTGGCG	p.Pro928fs	frameshift_variant, missense_variant	39/51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.2585_2590delCTGGCCinsTGGCG	p.Pro862fs	frameshift_variant, missense_variant	36/48		XP_011522643.1
COL1A1	XM_005257059.5	c.1865_1870delCTGGCCinsTGGCG	p.Pro622fs	frameshift_variant, missense_variant	26/38		XP_005257116.2
COL1A1	XM_005257058.5	c.2667+256_2667+261delCTGGCCinsTGGCG		intron_variant			XP_005257115.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.2783_2788delCTGGCCinsTGGCG	p.Pro928fs	frameshift_variant, missense_variant	39/51	1	NM_000088.4	ENSP00000225964.6

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Osteogenesis imperfecta type I Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 08, 2022

For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals affected with COL1A1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Pro928Leufs*180) 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

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555572456; hg19: chr17-48266779;