2-188999284-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_ModeratePM2PP5_Moderate

The NM_000090.4(COL3A1):​c.2023-1G>T variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,158 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

COL3A1
NM_000090.4 splice_acceptor, intron

Scores

5
1
Splicing: ADA: 1.000
2

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 9.68

Publications

0 publications found
Variant links:
Genes affected
COL3A1 (HGNC:2201): (collagen type III alpha 1 chain) This gene encodes the pro-alpha1 chains of type III collagen, a fibrillar collagen that is found in extensible connective tissues such as skin, lung, uterus, intestine and the vascular system, frequently in association with type I collagen. Mutations in this gene are associated with Ehlers-Danlos syndrome type IV, and with aortic and arterial aneurysms. [provided by R. Dalgleish, Feb 2008]
COL3A1 Gene-Disease associations (from GenCC):
  • autosomal dominant Ehlers-Danlos syndrome, vascular type
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Genomics England PanelApp
  • Ehlers-Danlos syndrome, vascular type
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • polymicrogyria with or without vascular-type Ehlers-Danlos syndrome
    Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.022494888 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.2, offset of -43, new splice context is: ttaaggtgctttgtttttAGctt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-188999284-G-T is Pathogenic according to our data. Variant chr2-188999284-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1522149.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000090.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL3A1
NM_000090.4
MANE Select
c.2023-1G>T
splice_acceptor intron
N/ANP_000081.2

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL3A1
ENST00000304636.9
TSL:1 MANE Select
c.2023-1G>T
splice_acceptor intron
N/AENSP00000304408.4
COL3A1
ENST00000450867.2
TSL:1
c.1924-1G>T
splice_acceptor intron
N/AENSP00000415346.2
COL3A1
ENST00000713745.1
c.1870-1G>T
splice_acceptor intron
N/AENSP00000519049.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152158
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1415514
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
699814
African (AFR)
AF:
0.00
AC:
0
AN:
32258
American (AMR)
AF:
0.00
AC:
0
AN:
37566
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25312
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37016
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80856
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50738
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5652
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1087488
Other (OTH)
AF:
0.00
AC:
0
AN:
58628
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152158
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74330
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Ehlers-Danlos syndrome, type 4 Pathogenic:1
Apr 04, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has been observed in individual(s) with COL3A1-related conditions (PMID: 19695909). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 29 of the COL3A1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in COL3A1 are known to be pathogenic (PMID: 24922459).

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.37
CADD
Pathogenic
34
DANN
Uncertain
1.0
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
1.0
D
PhyloP100
9.7
GERP RS
5.0
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.55
Position offset: 47
DS_AL_spliceai
1.0
Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs587779708; hg19: chr2-189864010; API