rs138722406

Positions:

chr11-44234224-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP3_ModerateBS2

The NM_207122.2(EXT2):c.1916C>T(p.Thr639Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000134 in 1,613,910 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

EXT2
NM_207122.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3B:1O:1

Conservation

PhyloP100: 7.91

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.907

BS2

High AC in GnomAd4 at 14 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
EXT2	NM_207122.2 link	c.1916C>T	p.Thr639Met	missense_variant	12/14	ENST00000533608.7	NP_997005.1	Q93063-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
EXT2	ENST00000533608.7 link	c.1916C>T	p.Thr639Met	missense_variant	12/14	1	NM_207122.2	ENSP00000431173.2		Q93063-1

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152134

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000943

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000757

AC:

AN:

251132

Hom.:

AF XY:

0.0000663

AC XY:

AN XY:

135724

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000980

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000115

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000139

AC:

203

AN:

1461776

Hom.:

Cov.:

AF XY:

0.000127

AC XY:

AN XY:

727170

show subpopulations

Gnomad4 AFR exome

AF:

0.000119

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.000536

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0000696

Gnomad4 FIN exome

AF:

0.0000562

Gnomad4 NFE exome

AF:

0.000146

Gnomad4 OTH exome

AF:

0.000132

GnomAD4 genome

AF:

0.0000920

AC:

AN:

152134

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74310

show subpopulations

Gnomad4 AFR

AF:

0.000121

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.000288

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000943

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000114

Hom.:

Bravo

AF:

0.0000982

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000741

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3Benign:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Seizures-scoliosis-macrocephaly syndrome

Pathogenic:1Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Jul 24, 2017	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Feb 04, 2025	- -

Exostoses, multiple, type 2

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 10, 2023	This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 639 of the EXT2 protein (p.Thr639Met). This variant is present in population databases (rs138722406, gnomAD 0.01%). This missense change has been observed in individual(s) with EXT2-related conditions (PMID: 30997052). This variant is also known as c.2015C>T (p.Thr672Met). ClinVar contains an entry for this variant (Variation ID: 134205). 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) performed at Invitae indicates that this missense variant is expected to disrupt EXT2 protein function with a positive predictive value of 80%. 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. -

Exostoses, multiple, type 2;C4225248:Seizures-scoliosis-macrocephaly syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 22, 2024

- -

not specified

Other:1

not provided, no classification provided

reference population

ITMI

Sep 19, 2013

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.74

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.44

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.94

D;.;.;D

Eigen

Pathogenic

0.99

Eigen_PC

Pathogenic

0.93

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

.;D;D;D

M_CAP

Uncertain

0.23

MetaRNN

Pathogenic

0.91

D;D;D;D

MetaSVM

Pathogenic

0.92

MutationAssessor

Pathogenic

3.7

H;.;.;H

PrimateAI

Pathogenic

0.87

PROVEAN

Pathogenic

-5.2

D;D;D;D

REVEL

Pathogenic

0.94

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0010

D;D;D;D

Polyphen

1.0

D;D;.;D

Vest4

0.92

MVP

1.0

MPC

0.84

ClinPred

0.97

GERP RS

5.6

Varity_R

0.81

gMVP

0.86

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over