11-44107972-T-G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6BS1

The NM_207122.2(EXT2):​c.260T>G​(p.Met87Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000324 in 1,614,200 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M87I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00030 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00033 ( 1 hom. )

Consequence

EXT2
NM_207122.2 missense

Scores

8
8
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:4O:1

Conservation

PhyloP100: 6.15

Publications

15 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: Likely_benign. The variant received -5 ACMG points.

BP6
Variant 11-44107972-T-G is Benign according to our data. Variant chr11-44107972-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 134211.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000302 (46/152332) while in subpopulation NFE AF = 0.000588 (40/68024). AF 95% confidence interval is 0.000444. There are 0 homozygotes in GnomAd4. There are 20 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
EXT2NM_207122.2 linkc.260T>G p.Met87Arg missense_variant Exon 2 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.260T>G p.Met87Arg missense_variant Exon 2 of 14 1 NM_207122.2 ENSP00000431173.2 Q93063-1

Frequencies

GnomAD3 genomes
AF:
0.000302
AC:
46
AN:
152214
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000327
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:
0.000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000354
AC:
89
AN:
251194
AF XY:
0.000390
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000521
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000608
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.000326
AC:
477
AN:
1461868
Hom.:
1
Cov.:
32
AF XY:
0.000303
AC XY:
220
AN XY:
727230
show subpopulations
African (AFR)
AF:
0.000119
AC:
4
AN:
33480
American (AMR)
AF:
0.000514
AC:
23
AN:
44720
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:
86256
European-Finnish (FIN)
AF:
0.0000562
AC:
3
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000381
AC:
424
AN:
1112002
Other (OTH)
AF:
0.000381
AC:
23
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
35
70
106
141
176
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<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:
0.000302
AC:
46
AN:
152332
Hom.:
0
Cov.:
32
AF XY:
0.000269
AC XY:
20
AN XY:
74486
show subpopulations
African (AFR)
AF:
0.0000240
AC:
1
AN:
41582
American (AMR)
AF:
0.000327
AC:
5
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000588
AC:
40
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
2
4
7
9
11
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:
0.000493
Hom.:
1
Bravo
AF:
0.000268
TwinsUK
AF:
0.000809
AC:
3
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000814
AC:
7
ExAC
AF:
0.000338
AC:
41
EpiCase
AF:
0.000709
EpiControl
AF:
0.000830

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:4Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Exostoses, multiple, type 2 Benign:3
Oct 08, 2021
Mendelics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 23, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided Uncertain:1Benign:1
Mar 22, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 26246518) -

Nov 03, 2021
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1Other:1
Sep 19, 2013
ITMI
Significance:not provided
Review Status:no classification provided
Collection Method:reference population

- -

Nov 19, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: EXT2 c.260T>G (p.Met87Arg) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00035 in 251194 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in EXT2 causing Seizures, Scoliosis, And Macrocephaly Syndrome, allowing no conclusion about variant significance. c.260T>G has been reported in the literature in the homozygous state in cis with another variant of uncertain significance in four related individuals affected with Seizures, Scoliosis, And Macrocephaly Syndrome without osteochondromas reported in the family and has also been reported without strong evidence for causality in at least one individual with multiple osteochondromas (e.g. Farhan_2015, Gnoli_2024). These reports do not provide unequivocal conclusions about association of the variant with Seizures, Scoliosis, And Macrocephaly Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function and found that the variant results in >75%-90% of WT protein expression in vitro (Farhan_2015). The following publications have been ascertained in the context of this evaluation (PMID: 26246518, 38351015). ClinVar contains an entry for this variant (Variation ID: 134211). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.85
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Pathogenic
0.49
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.76
D;.;.;.;D
Eigen
Uncertain
0.47
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.95
.;D;D;D;D
M_CAP
Pathogenic
0.30
D
MetaRNN
Uncertain
0.61
D;D;D;D;D
MetaSVM
Pathogenic
0.95
D
MutationAssessor
Uncertain
2.1
M;.;M;.;M
PhyloP100
6.2
PrimateAI
Pathogenic
0.85
D
PROVEAN
Uncertain
-2.5
N;D;N;D;N
REVEL
Pathogenic
0.86
Sift
Benign
0.055
T;D;T;D;T
Sift4G
Benign
0.22
T;D;T;T;T
Polyphen
0.94
P;.;D;.;P
Vest4
0.97
MVP
1.0
MPC
0.83
ClinPred
0.20
T
GERP RS
5.5
Varity_R
0.65
gMVP
0.97
Mutation Taster
=0/100
disease causing (ClinVar)

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: rs140075817; hg19: chr11-44129522; API