17-50199822-C-A

Position:

• chr17-50199822-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000088.4(COL1A1):​c.229G>T​(p.Glu77Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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)
• Consequence: COL1A1 NM_000088.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.32

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 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 17-50199822-C-A is Pathogenic according to our data. Variant chr17-50199822-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 526853.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.229G>T	p.Glu77Ter	stop_gained	2/51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.229G>T	p.Glu77Ter	stop_gained	2/48		XP_011522643.1
COL1A1	XM_005257058.5	c.229G>T	p.Glu77Ter	stop_gained	2/49		XP_005257115.2
COL1A1	XM_005257059.5	c.229G>T	p.Glu77Ter	stop_gained	2/38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.229G>T	p.Glu77Ter	stop_gained	2/51	1	NM_000088.4	ENSP00000225964	P1
COL1A1	ENST00000507689.1	c.283G>T	p.Glu95Ter	stop_gained	1/4	2		ENSP00000460459
COL1A1	ENST00000474644.1	n.348G>T		non_coding_transcript_exon_variant	2/4	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

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 26, 2020

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in COL1A1 are known to be pathogenic (PMID: 7942841, 9295084, 9443882). This variant has not been reported in the literature in individuals with COL1A1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Glu77*) in the COL1A1 gene. It is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Uncertain	0.88	D
MutationTaster	Benign	1.0	A
Vest4		0.73
GERP RS		4.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs753683126; hg19: chr17-48277183;