17-50190329-G-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate

The NM_000088.4(COL1A1):c.2449C>A(p.Pro817Thr) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000278 in 1,439,096 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. P817P) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

COL1A1
NM_000088.4 missense, splice_region

Scores

Splicing: ADA: 0.5039

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 10.0

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM1

In a modified_residue 4-hydroxyproline (size 0) in uniprot entity CO1A1_HUMAN

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 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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.891

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL1A1	NM_000088.4 link	c.2449C>A	p.Pro817Thr	missense_variant, splice_region_variant	Exon 35 of 51	ENST00000225964.10	NP_000079.2	P02452
COL1A1	XM_011524341.2 link	c.2251C>A	p.Pro751Thr	missense_variant, splice_region_variant	Exon 32 of 48		XP_011522643.1
COL1A1	XM_005257058.5 link	c.2449C>A	p.Pro817Thr	missense_variant, splice_region_variant	Exon 35 of 49		XP_005257115.2
COL1A1	XM_005257059.5 link	c.1531C>A	p.Pro511Thr	missense_variant, splice_region_variant	Exon 22 of 38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10 link	c.2449C>A	p.Pro817Thr	missense_variant, splice_region_variant	Exon 35 of 51	1	NM_000088.4	ENSP00000225964.6		P02452
COL1A1	ENST00000494334.1 link	n.376C>A		non_coding_transcript_exon_variant	Exon 2 of 2	2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000400

AC:

AN:

249800

Hom.:

AF XY:

0.00000738

AC XY:

AN XY:

135544

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000886

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000278

AC:

AN:

1439096

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

716924

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000367

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Osteogenesis imperfecta type I

Uncertain:1

Aug 24, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. This variant has not been reported in the literature in individuals affected with COL1A1-related conditions. This variant is present in population databases (rs769167761, ExAC 0.002%). This sequence change replaces proline with threonine at codon 817 of the COL1A1 protein (p.Pro817Thr). The proline residue is highly conserved and there is a small physicochemical difference between proline and threonine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Pathogenic

0.14

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.99

M_CAP

Pathogenic

0.62

MetaRNN

Pathogenic

0.89

MetaSVM

Pathogenic

1.1

PrimateAI

Pathogenic

0.84

PROVEAN

Pathogenic

-5.6

REVEL

Pathogenic

0.81

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.054

Vest4

0.63

MutPred

0.55

Gain of phosphorylation at P817 (P = 0.0031);

MVP

0.88

MPC

0.63

ClinPred

0.99

GERP RS

5.1

gMVP

0.68

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.50

dbscSNV1_RF

Benign

0.60

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over