rs371233961

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000127.3(EXT1):​c.1135G>T​(p.Val379Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,976 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V379I) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

EXT1
NM_000127.3 missense

Scores

9
7
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.25

Publications

3 publications found
Variant links:
Genes affected
EXT1 (HGNC:3512): (exostosin glycosyltransferase 1) This gene encodes an endoplasmic reticulum-resident type II transmembrane glycosyltransferase involved in the chain elongation step of heparan sulfate biosynthesis. Mutations in this gene cause the type I form of multiple exostoses. [provided by RefSeq, Jul 2008]
EXT1 Gene-Disease associations (from GenCC):
  • exostoses, multiple, type 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen
  • chondrosarcoma
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • hereditary multiple osteochondromas
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.953

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
EXT1NM_000127.3 linkc.1135G>T p.Val379Phe missense_variant Exon 3 of 11 ENST00000378204.7 NP_000118.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
EXT1ENST00000378204.7 linkc.1135G>T p.Val379Phe missense_variant Exon 3 of 11 1 NM_000127.3 ENSP00000367446.3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152174
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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
AF:
6.84e-7
AC:
1
AN:
1461802
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111936
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60388
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
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152174
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74344
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.0000654
AC:
1
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
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:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
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
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Multiple congenital exostosis Uncertain:1
Aug 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 379 of the EXT1 protein (p.Val379Phe). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with EXT1-related conditions. 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on EXT1 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.60
BayesDel_addAF
Pathogenic
0.48
D
BayesDel_noAF
Pathogenic
0.45
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.97
D
Eigen
Uncertain
0.24
Eigen_PC
Uncertain
0.30
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.40
D
MetaRNN
Pathogenic
0.95
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
1.9
L
PhyloP100
2.3
PrimateAI
Uncertain
0.69
T
PROVEAN
Uncertain
-2.7
D
REVEL
Pathogenic
0.83
Sift
Benign
0.069
T
Sift4G
Uncertain
0.0040
D
Polyphen
0.42
B
Vest4
0.90
MutPred
0.79
Loss of sheet (P = 0.1907);
MVP
1.0
MPC
1.3
ClinPred
0.96
D
GERP RS
3.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.36
gMVP
0.97
Mutation Taster
=28/72
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs371233961; hg19: chr8-118847712; API