8-117799758-T-C

Variant summary

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

The NM_000127.3(EXT1):​c.2195A>G​(p.Gln732Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,614,056 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

EXT1
NM_000127.3 missense

Scores

4
10
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.02

Publications

0 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: 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
EXT1NM_000127.3 linkc.2195A>G p.Gln732Arg missense_variant Exon 11 of 11 ENST00000378204.7 NP_000118.2 Q16394

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
EXT1ENST00000378204.7 linkc.2195A>G p.Gln732Arg missense_variant Exon 11 of 11 1 NM_000127.3 ENSP00000367446.3 Q16394
EXT1ENST00000684189.1 linkn.1662A>G non_coding_transcript_exon_variant Exon 11 of 11
EXT1ENST00000684443.1 linkn.2321A>G non_coding_transcript_exon_variant Exon 2 of 2
EXT1ENST00000437196.1 linkn.*1086A>G downstream_gene_variant 5 ENSP00000407299.1 F8WF54

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152164
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461892
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727248
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:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
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
AF:
0.00000657
AC:
1
AN:
152164
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41450
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
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:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
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

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:
0.00000378

ClinVar

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

Submissions by phenotype

Multiple congenital exostosis Uncertain:1
Jun 27, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamine with arginine at codon 732 of the EXT1 protein (p.Gln732Arg). The glutamine residue is highly conserved and there is a small physicochemical difference between glutamine and arginine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with EXT1-related conditions. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.73
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.26
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.44
T
Eigen
Uncertain
0.22
Eigen_PC
Uncertain
0.38
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.89
D
M_CAP
Benign
0.072
D
MetaRNN
Uncertain
0.67
D
MetaSVM
Uncertain
0.38
D
MutationAssessor
Benign
1.4
L
PhyloP100
8.0
PrimateAI
Uncertain
0.78
T
PROVEAN
Benign
-1.5
N
REVEL
Uncertain
0.51
Sift
Uncertain
0.026
D
Sift4G
Benign
0.23
T
Polyphen
0.79
P
Vest4
0.76
MutPred
0.28
Gain of MoRF binding (P = 0.0365);
MVP
0.96
MPC
2.4
ClinPred
0.88
D
GERP RS
6.0
Varity_R
0.34
gMVP
0.62
Mutation Taster
=14/86
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
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: rs1188494289; hg19: chr8-118811997; API