rs1555572120

Variant names:

• chr17-50187959-T-TG
• rs1555572120
• NM_000088.4:c.3285dupC

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000088.4(COL1A1):​c.3285dupC​(p.Lys1096GlnfsTer3) 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: 33)
• Consequence: COL1A1 NM_000088.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.88
• Publications: 0 publications found

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]

COL1A1 Gene-Disease associations (from GenCC):

• Caffey disease

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), G2P, ClinGen
• combined osteogenesis imperfecta and Ehlers-Danlos syndrome 1

  Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: Ambry Genetics, ClinGen
• Ehlers-Danlos syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• Ehlers-Danlos syndrome, arthrochalasia type

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, PanelApp Australia, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
• osteogenesis imperfecta type 1

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• osteogenesis imperfecta type 2

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• osteogenesis imperfecta type 3

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• osteogenesis imperfecta type 4

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet, ClinGen
• Ehlers-Danlos syndrome, classic type, 1

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• Ehlers-Danlos syndrome, classic type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Ehlers-Danlos/osteogenesis imperfecta syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• high bone mass osteogenesis imperfecta

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 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 17-50187959-T-TG is Pathogenic according to our data. Variant chr17-50187959-T-TG is described in ClinVar as Pathogenic. ClinVar VariationId is 456766.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.3285dupC	p.Lys1096GlnfsTer3	frameshift_variant	Exon 45 of 51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.3087dupC	p.Lys1030GlnfsTer3	frameshift_variant	Exon 42 of 48		XP_011522643.1
COL1A1	XM_005257058.5	c.3015dupC	p.Lys1006GlnfsTer3	frameshift_variant	Exon 43 of 49		XP_005257115.2
COL1A1	XM_005257059.5	c.2367dupC	p.Lys790GlnfsTer3	frameshift_variant	Exon 32 of 38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.3285dupC	p.Lys1096GlnfsTer3	frameshift_variant	Exon 45 of 51	1	NM_000088.4	ENSP00000225964.6
COL1A1	ENST00000486572.1	n.483dupC		non_coding_transcript_exon_variant	Exon 2 of 2	3
COL1A1	ENST00000511732.1	n.721dupC		non_coding_transcript_exon_variant	Exon 2 of 2	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Osteogenesis imperfecta type I Pathogenic:1

Oct 26, 2016

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. Loss-of-function variants in COL1A1 are known to be pathogenic. This particular variant has been reported in the literature in an individual affected with osteogenesis imperfecta type I (PMID: 7942841). Due to legacy nomenclature, this exon is also known as exon 46 in the literature. This sequence change inserts 1 nucleotide in exon 45 of the COL1A1 mRNA (c.3285dupC), causing a frameshift at codon 1096. This creates a premature translational stop signal (p.Lys1096Glnfs*3) and is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.9
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1555572120; hg19: chr17-48265320;