NM_000088.4:c.3459T>G

Variant names:

• chr17-50187087-A-C
• rs1800218
• NM_000088.4:c.3459T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_000088.4(COL1A1):​c.3459T>G​(p.Asp1153Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,826 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. D1153D) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 0.841
• 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.8

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.3459T>G	p.Asp1153Glu	missense	Exon 47 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.3459T>G	p.Asp1153Glu	missense	Exon 47 of 51	ENSP00000225964.6
	COL1A1	ENST00000510710.3	TSL:2	n.36T>G		non_coding_transcript_exon	Exon 1 of 2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460826 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726630

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44472

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26092

East Asian (EAS) AF: 0.00 AC: 0 AN: 39664

South Asian (SAS) AF: 0.00 AC: 0 AN: 86082

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53292

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111630

Other (OTH) AF: 0.00 AC: 0 AN: 60356

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Osteogenesis imperfecta type I Uncertain:1

Dec 23, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt COL1A1 protein function. This variant has not been reported in the literature in individuals with COL1A1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces aspartic acid with glutamic acid at codon 1153 of the COL1A1 protein (p.Asp1153Glu). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and glutamic acid.

Ehlers-Danlos syndrome;C0020497:Infantile cortical hyperostosis;C0029434:Osteogenesis imperfecta;C4551623:Ehlers-Danlos syndrome, arthrochalasia type Other:1

GenomeConnect, ClinGen

Significance: not provided

Review Status: no classification provided

Collection Method: phenotyping only

Variant classified as Uncertain significance and reported on 12-30-2020 by Invitae. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.31
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
CADD	Benign	16
DANN	Benign	0.96
Eigen	Benign	-0.17
Eigen_PC	Benign	-0.28
FATHMM_MKL	Uncertain	0.89	D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.80	D
MetaSVM	Uncertain	0.18	D
PhyloP100		0.84
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-2.8	D
REVEL	Uncertain	0.62
Sift	Benign	0.11	T
Sift4G	Benign	0.37	T
Vest4		0.71
MutPred		0.22		Gain of methylation at K1152 (P = 0.1279)
MVP		0.92
MPC		0.52
ClinPred		0.89	D
GERP RS		-3.3
gMVP		0.80
Mutation Taster		=50/50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1800218; hg19: chr17-48264448;