rs146387238

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_021871.4(FGA):​c.510+1G>T variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.000115 in 1,613,630 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 Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 30)
Exomes 𝑓: 0.00012 ( 0 hom. )

Consequence

FGA
NM_021871.4 splice_donor, intron

Scores

4
2
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 6.17

Publications

13 publications found
Variant links:
Genes affected
FGA (HGNC:3661): (fibrinogen alpha chain) This gene encodes the alpha subunit of the coagulation factor fibrinogen, which is a component of the blood clot. Following vascular injury, the encoded preproprotein is proteolytically processed by thrombin during the conversion of fibrinogen to fibrin. Mutations in this gene lead to several disorders, including dysfibrinogenemia, hypofibrinogenemia, afibrinogenemia and renal amyloidosis. Alternative splicing results in multiple transcript variants, at least one of which encodes an isoform that undergoes proteolytic processing. [provided by RefSeq, Jan 2016]
FGA Gene-Disease associations (from GenCC):
  • familial dysfibrinogenemia
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • congenital afibrinogenemia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • congenital fibrinogen deficiency
    Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
  • familial visceral amyloidosis
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • thrombophilia
    Inheritance: AR, AD Classification: STRONG Submitted by: Genomics England PanelApp
  • AFib amyloidosis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial hypofibrinogenemia
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.6, offset of 4, new splice context is: taaGTatgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PP5
Variant 4-154587511-C-A is Pathogenic according to our data. Variant chr4-154587511-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 16415.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FGANM_021871.4 linkc.510+1G>T splice_donor_variant, intron_variant Intron 4 of 4 ENST00000403106.8 NP_068657.1 P02671-2
FGANM_000508.5 linkc.510+1G>T splice_donor_variant, intron_variant Intron 4 of 5 NP_000499.1 P02671-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FGAENST00000403106.8 linkc.510+1G>T splice_donor_variant, intron_variant Intron 4 of 4 1 NM_021871.4 ENSP00000385981.3 P02671-2
FGAENST00000651975.2 linkc.510+1G>T splice_donor_variant, intron_variant Intron 4 of 5 ENSP00000498441.1 P02671-1
ENSG00000306549ENST00000819308.1 linkn.137+747C>A intron_variant Intron 1 of 1

Frequencies

GnomAD3 genomes
AF:
0.0000789
AC:
12
AN:
152072
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.0000967
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:
0.000118
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000557
AC:
14
AN:
251372
AF XY:
0.0000662
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000968
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000118
AC:
173
AN:
1461558
Hom.:
0
Cov.:
33
AF XY:
0.000111
AC XY:
81
AN XY:
727092
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33462
American (AMR)
AF:
0.000134
AC:
6
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39660
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53398
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.000148
AC:
164
AN:
1111780
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
10
19
29
38
48
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000789
AC:
12
AN:
152072
Hom.:
0
Cov.:
30
AF XY:
0.0000808
AC XY:
6
AN XY:
74288
show subpopulations
African (AFR)
AF:
0.0000967
AC:
4
AN:
41384
American (AMR)
AF:
0.00
AC:
0
AN:
15250
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000118
AC:
8
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000115
Hom.:
0
Bravo
AF:
0.0000642
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000659
AC:
8
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Jul 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is present in population databases (rs146387238, gnomAD 0.009%). For these reasons, this variant has been classified as Pathogenic. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 16415). This variant is also known as IVS4+1G>T. Disruption of this splice site has been observed in individuals with hereditary fibrinogen abnormalities (PMID: 10891444, 30349899). This sequence change affects a donor splice site in intron 4 of the FGA gene. While this variant is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. -

Sep 19, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 15, 2023
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 25525159, 34255402, 31064749, 30349899, 10891444) -

Familial hypodysfibrinogenemia Pathogenic:1
Apr 01, 2004
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Familial visceral amyloidosis, Ostertag type;C0272350:Familial dysfibrinogenemia;C2584774:Congenital afibrinogenemia Pathogenic:1
Apr 06, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Congenital afibrinogenemia Pathogenic:1
Jul 01, 2000
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Hypofibrinogenemia Pathogenic:1
Feb 01, 2019
NIHR Bioresource Rare Diseases, University of Cambridge
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Familial dysfibrinogenemia Pathogenic:1
Jul 29, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: FGA c.510+1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing and loss of FGA function. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 5.6e-05 in 251372 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in FGA causing Dysfibrinogenemia, Congenital, allowing no conclusion about variant significance. c.510+1G>T has been reported in the literature in multiple individuals affected with Afibrinogenaemia (e.g. Neerman-Arbez_2000). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 10891444). ClinVar contains an entry for this variant (Variation ID: 16415). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.33
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Uncertain
0.97
D
PhyloP100
6.2
GERP RS
6.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=0/100
disease causing (ClinVar)

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_DG_spliceai
0.74
Position offset: -3
DS_DL_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: rs146387238; hg19: chr4-155508663; API