rs763718818

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_207122.2(EXT2):​c.937C>G​(p.Gln313Glu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000137 in 1,460,134 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

EXT2
NM_207122.2 missense, splice_region

Scores

4
9
6
Splicing: ADA: 0.9286
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.06

Publications

4 publications found
Variant links:
Genes affected
EXT2 (HGNC:3513): (exostosin glycosyltransferase 2) This gene encodes one of two glycosyltransferases involved in the chain elongation step of heparan sulfate biosynthesis. Mutations in this gene cause the type II form of multiple exostoses. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Jul 2008]
EXT2 Gene-Disease associations (from GenCC):
  • exostoses, multiple, type 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, G2P
  • seizures-scoliosis-macrocephaly syndrome
    Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet
  • 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: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
EXT2NM_207122.2 linkc.937C>G p.Gln313Glu missense_variant, splice_region_variant Exon 5 of 14 ENST00000533608.7 NP_997005.1 Q93063-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
EXT2ENST00000533608.7 linkc.937C>G p.Gln313Glu missense_variant, splice_region_variant Exon 5 of 14 1 NM_207122.2 ENSP00000431173.2 Q93063-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250756
AF XY:
0.00000738
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1460134
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
726444
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33422
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86204
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53148
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4648
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111914
Other (OTH)
AF:
0.00
AC:
0
AN:
60246
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.029673), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
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

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
Cov.:
32
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

Exostoses, multiple, type 2 Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.12
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Pathogenic
0.22
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.71
D;.;.;D
Eigen
Uncertain
0.23
Eigen_PC
Uncertain
0.39
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.95
.;D;D;D
M_CAP
Uncertain
0.17
D
MetaRNN
Uncertain
0.58
D;D;D;D
MetaSVM
Pathogenic
0.79
D
MutationAssessor
Benign
1.9
L;L;.;L
PhyloP100
7.1
PrimateAI
Uncertain
0.60
T
PROVEAN
Benign
-0.82
N;N;N;N
REVEL
Uncertain
0.58
Sift
Benign
0.16
T;T;T;T
Sift4G
Benign
0.67
T;T;T;T
Polyphen
0.18
B;B;.;B
Vest4
0.77
MutPred
0.59
Loss of sheet (P = 0.1501);Loss of sheet (P = 0.1501);.;Loss of sheet (P = 0.1501);
MVP
0.97
MPC
0.34
ClinPred
0.48
T
GERP RS
5.8
Varity_R
0.21
gMVP
0.74
Mutation Taster
=49/51
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.93
dbscSNV1_RF
Benign
0.58
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

Other links and lift over

dbSNP: rs763718818; hg19: chr11-44146532; API