rs1011196447

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1_ModeratePP5_Very_Strong

The NM_001244710.2(GFPT1):​c.686-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000113 in 1,589,450 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

GFPT1
NM_001244710.2 splice_acceptor, intron

Scores

3
3
1
Splicing: ADA: 0.9434
1
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 4.94

Publications

1 publications found
Variant links:
Genes affected
GFPT1 (HGNC:4241): (glutamine--fructose-6-phosphate transaminase 1) This gene encodes the first and rate-limiting enzyme of the hexosamine pathway and controls the flux of glucose into the hexosamine pathway. The product of this gene catalyzes the formation of glucosamine 6-phosphate. [provided by RefSeq, Sep 2008]
GFPT1 Gene-Disease associations (from GenCC):
  • congenital myasthenic syndrome 12
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics, Illumina
  • congenital myasthenic syndromes with glycosylation defect
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.025714286 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.7, offset of 4, new splice context is: tgttgtgtatccttggctAGgac. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PP5
Variant 2-69354314-T-C is Pathogenic according to our data. Variant chr2-69354314-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 540353.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
GFPT1NM_001244710.2 linkc.686-2A>G splice_acceptor_variant, intron_variant Intron 8 of 19 ENST00000357308.9 NP_001231639.1 Q06210-1
GFPT1NM_002056.4 linkc.685+175A>G intron_variant Intron 8 of 18 NP_002047.2 Q06210-2
GFPT1XM_017003801.2 linkc.761-2A>G splice_acceptor_variant, intron_variant Intron 8 of 19 XP_016859290.1
GFPT1XM_017003802.3 linkc.760+175A>G intron_variant Intron 8 of 18 XP_016859291.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GFPT1ENST00000357308.9 linkc.686-2A>G splice_acceptor_variant, intron_variant Intron 8 of 19 5 NM_001244710.2 ENSP00000349860.4 Q06210-1
GFPT1ENST00000361060.5 linkc.685+175A>G intron_variant Intron 8 of 18 1 ENSP00000354347.4 Q06210-2
GFPT1ENST00000674507.1 linkc.685+175A>G intron_variant Intron 8 of 17 ENSP00000501332.1 A0A6I8PTT9
GFPT1ENST00000674438.1 linkc.469+175A>G intron_variant Intron 6 of 16 ENSP00000501469.1 A0A6I8PRN4

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152204
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.000478
GnomAD2 exomes
AF:
0.0000227
AC:
5
AN:
219992
AF XY:
0.0000332
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000121
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000992
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000104
AC:
15
AN:
1437246
Hom.:
0
Cov.:
28
AF XY:
0.0000126
AC XY:
9
AN XY:
714752
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33296
American (AMR)
AF:
0.000206
AC:
9
AN:
43662
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25850
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39514
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84888
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
38860
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5742
European-Non Finnish (NFE)
AF:
0.00000181
AC:
2
AN:
1105454
Other (OTH)
AF:
0.0000500
AC:
3
AN:
59980
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
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

Exome 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
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.000131
AC:
2
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68036
Other (OTH)
AF:
0.000478
AC:
1
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 12 Pathogenic:5
Jan 03, 2022
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Canonical splice site: predicted to alter splicing and result in a loss or disruption of normal protein function through protein truncation. Multiple pathogenic variants are reported in the predicted truncated region (PVS1_VS).The variant has been reported at least twice as pathogenic/likely pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000540353). It is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.000024, PM2_M). The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least one similarly affected unrelated individual (PMID:23794683, PM3_M). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

Jan 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 8 of the GFPT1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (no rsID available, gnomAD 0.02%). Disruption of this splice site has been observed in individuals with congenital myasthenic syndrome (PMID: 23794683, 28464723, 29054425). ClinVar contains an entry for this variant (Variation ID: 540353). Studies have shown that disruption of this splice site results in deletion of the first 4 nucleotides of the muscle-specific exon of GFPT1, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 23794683). For these reasons, this variant has been classified as Pathogenic. -

Oct 04, 2021
Pars Genome Lab
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 15, 2023
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 02, 2023
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

The homozygous c.686-2A>G variant in GFPT1 was identified by our study in one individual with congenital myasthenic syndrome. The c.686-2A>G variant in GFPT1 has been previously reported in at least four unrelated individuals with congenital myasthenic syndrome 12 (PMID: 28464723, PMID: 29054425, PMID: 32403337, PMID: 32528171, PMID: 23794683) but has been identified in 0.015% (5/33776) of Latino/Admixed American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs772941684). Although this variant has been seen in the general population in a heterozygous state, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (Variation ID: 540353) and has been interpreted as pathogenic by Invitae, Illumina, 3billion, Pars Genome Lab, and Kariminejad - Najmabadi Pathology & Genetics Center. Of these four individuals with congenital myasthenic syndrome 12 (PMID: 28464723, PMID: 29054425, PMID: 32403337, PMID: 32528171, PMID: 23794683), three were homozygotes (PMID: 28464723, PMID: 29054425, PMID: 32403337, PMID: 32528171) and one was a compound heterozygote who carried a likely pathogenic variant in trans (PMID: 23794683, ClinVar Variation ID: 859066), which increases the likelihood that the c.686-2A>G variant is pathogenic. RT-PCR and cDNA analysis of patient muscle tissue showed that the c.686-2A>G variant resulted in a 4 base-pair deletion of the muscle-specific exon of GFPT1, leading to frameshift and a premature stop codon 56 amino acids downstream (PMID: 23794683). This variant is located in the 3' splice region. Computational tools predict a splicing impact, though this information is not predictive enough to determine pathogenicity. Loss of function of the GFPT1 gene is strongly associated to autosomal recessive congenital myasthenic syndrome 12. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive congenital myasthenic syndrome 12. ACMG/AMP Criteria applied: PVS1_Strong, PM3_Strong, PS3_Supporting (Richards 2015). -

GFPT1-related myasthenic syndrome Pathogenic:1
Jan 04, 2022
Illumina Laboratory Services, Illumina
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The GFPT1 c.686-2A>G variant results in the substitution of an adenine within the consensus splice acceptor site with a guanine, which may result in splicing defects. Across a selection of the available literature, this variant has been identified in at least five individuals with a congenital myasthenic syndrome or limb-girdle muscle weakness, including in a confirmed or presumed homozygous state in four individuals, and in a compound heterozygous state in one individual (Selcen et al. 2013; Yiş et al. 2017; Natera-de Benito et al. 2017; Gonzalez-Quereda et al. 2020; Töpf et al. 2020). The highest frequency of this allele in the Genome Aggregation Database is 0.000148 in the Latino/Admixed American population (version 2.1.1). This variant precedes the muscle-specific exon of GFPT1, and patient cDNA studies have shown that it eliminates the first four nucleotides of this exon and results in missense changes of 56 amino acids and a premature stop codon (Selcen et al. 2013). This variant was identified in a homozygous state. Based on the available evidence, the c.686-2A>G variant is classified as pathogenic for GFPT1-related myasthenic syndrome. -

GFPT1-related disorder Pathogenic:1
May 10, 2023
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The GFPT1 c.686-2A>G variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. This variant has been reported in the homozygous or compound heterozygous state in multiple individuals with congenital myasthenic syndrome (see for example, Selcen et al. 2013. PubMed ID: 23794683; Yiş U et al. 2017. PubMed ID: 28464723; Natera-de Benito et al. 2017. PubMed ID: 29054425). In vitro functional study suggests this variant impacts protein function (Patient 6 in Figure 3, Selcen et al. 2013. PubMed ID: 23794683). This variant is reported in 0.015% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-69581446-T-C). Variants that disrupt the consensus splice acceptor site in GFPT1 are expected to be pathogenic. This variant is interpreted as pathogenic.. -

Congenital myasthenic syndrome 4C;C3552335:Congenital myasthenic syndrome 12 Pathogenic:1
May 12, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
Sep 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

GFPT1: PVS1, PM3, PM2:Supporting, PS3:Supporting -

Abnormality of the musculature Pathogenic:1
Jul 10, 2021
Kariminejad - Najmabadi Pathology & Genetics Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Uncertain
0.16
D
BayesDel_noAF
Pathogenic
0.21
CADD
Pathogenic
32
DANN
Uncertain
0.99
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Uncertain
0.94
D
PhyloP100
4.9
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Mutation Taster
=2/98
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.94
dbscSNV1_RF
Pathogenic
0.80
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

Publications

Other links and lift over

dbSNP: rs1011196447; hg19: chr2-69581446; API