17-50194807-G-T

Variant names:

• chr17-50194807-G-T
• rs751299130
• NM_000088.4:c.1375C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 5P and 5B. PM1 PM2 PP2 BP6 BS2

The NM_000088.4(COL1A1):​c.1375C>A​(p.Pro459Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000353 in 1,417,848 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P459H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000035 (0 hom.)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 4.22
• 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: Uncertain_significance. The variant received 0 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_000088.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the COL1A1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 368 curated pathogenic missense variants (we use a threshold of 10). The gene has 98 curated benign missense variants. Gene score misZ: 3.5319 (above the threshold of 3.09). Trascript score misZ: 5.7733 (above the threshold of 3.09). GenCC associations: The gene is linked to high bone mass osteogenesis imperfecta, Ehlers-Danlos syndrome, arthrochalasia type, combined osteogenesis imperfecta and Ehlers-Danlos syndrome 1, Caffey disease, osteogenesis imperfecta type 4, osteogenesis imperfecta type 3, Ehlers-Danlos syndrome, classic type, Ehlers-Danlos syndrome, osteogenesis imperfecta type 2, osteogenesis imperfecta type 1, Ehlers-Danlos syndrome, classic type, 1, Ehlers-Danlos/osteogenesis imperfecta syndrome.
• BP6: Variant 17-50194807-G-T is Benign according to our data. Variant chr17-50194807-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 388459.
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000088.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL1A1	NM_000088.4	MANE Select	c.1375C>A	p.Pro459Thr	missense	Exon 21 of 51	NP_000079.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL1A1	ENST00000225964.10	TSL:1 MANE Select	c.1375C>A	p.Pro459Thr	missense	Exon 21 of 51	ENSP00000225964.6
	COL1A1	ENST00000471344.1	TSL:2	n.319C>A		non_coding_transcript_exon	Exon 5 of 8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000398 AC: 7 AN: 176074 AF XY: 0.0000210

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000257

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000353 AC: 5 AN: 1417848 Hom.: 0 Cov.: 35 AF XY: 0.00000285 AC XY: 2 AN XY: 701740

African (AFR) AF: 0.00 AC: 0 AN: 32142

American (AMR) AF: 0.000130 AC: 5 AN: 38534

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25404

East Asian (EAS) AF: 0.00 AC: 0 AN: 36890

South Asian (SAS) AF: 0.00 AC: 0 AN: 81664

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50046

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5662

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1088912

Other (OTH) AF: 0.00 AC: 0 AN: 58594

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.0000336 AC: 4

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Infantile cortical hyperostosis;C0023931:Osteogenesis imperfecta type I;C0029458:Postmenopausal osteoporosis;C0268358:Osteogenesis imperfecta, perinatal lethal;C0268362:Osteogenesis imperfecta type III;C0268363:Osteogenesis imperfecta with normal sclerae, dominant form;C4551623:Ehlers-Danlos syndrome, arthrochalasia type Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Aug 10, 2016

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The P459T variant in the COL1A1 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The P459T variant was not observed in approximately 6,400 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The P459T variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved in mammals. In silico analysis predicts this variant is probably damaging to the protein structure/function. We interpret P459T as a variant of uncertain significance.

Osteogenesis imperfecta type I Benign:1

Jan 16, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.063
BayesDel_addAF	Benign	-0.014	T
BayesDel_noAF	Uncertain	0.020
CADD	Uncertain	24
DANN	Benign	0.95
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Pathogenic	0.34	D
MetaRNN	Uncertain	0.45	T
MetaSVM	Pathogenic	0.96	D
PhyloP100		4.2
PrimateAI	Uncertain	0.56	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.73
Sift	Benign	0.057	T
Sift4G	Benign	0.32	T
Vest4		0.61
MutPred		0.47		Gain of phosphorylation at P459 (P = 0.0092)
MVP		0.77
MPC		0.63
ClinPred		0.26	T
GERP RS		5.6
gMVP		0.81
Mutation Taster		=32/68	disease causing

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

Other links and lift over

dbSNP: rs751299130; hg19: chr17-48272168;