Genetic Variant EXT2:p.Pro247Arg (chr11-44114298-C-G) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_207122.2(EXT2):c.740C>G(p.Pro247Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,612,490 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: 0.0000075 ( 0 hom. )

Consequence

EXT2
NM_207122.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.76

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 -4 ACMG points.

BS2

High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
EXT2	NM_207122.2 link	c.740C>G	p.Pro247Arg	missense_variant	Exon 4 of 14	ENST00000533608.7	NP_997005.1	Q93063-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
EXT2	ENST00000533608.7 link	c.740C>G	p.Pro247Arg	missense_variant	Exon 4 of 14	1	NM_207122.2	ENSP00000431173.2		Q93063-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

251360

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135842

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS 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:

0.00000753

AC:

AN:

1460364

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

726634

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000246

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152126

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74296

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Exostoses, multiple, type 2

Uncertain:1

Jun 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 247 of the EXT2 protein (p.Pro247Arg). This variant is present in population databases (rs372237191, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with EXT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1040250). 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 not expected to disrupt EXT2 protein function with a negative 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.091

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Pathogenic

0.24

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.76

D;.;.;D

Eigen

Benign

0.13

Eigen_PC

Uncertain

0.34

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.92

.;D;D;D

M_CAP

Benign

0.066

MetaRNN

Uncertain

0.61

D;D;D;D

MetaSVM

Uncertain

0.46

MutationAssessor

Uncertain

2.3

M;M;.;M

PrimateAI

Benign

0.44

PROVEAN

Benign

-0.99

N;N;N;N

REVEL

Uncertain

0.54

Sift

Benign

0.19

T;T;T;T

Sift4G

Benign

0.22

T;T;T;T

Polyphen

0.0070

B;B;.;B

Vest4

0.74

MutPred

0.53

Loss of glycosylation at P247 (P = 0.0222);Loss of glycosylation at P247 (P = 0.0222);.;Loss of glycosylation at P247 (P = 0.0222);

MVP

1.0

MPC

0.23

ClinPred

0.21

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.12

gMVP

0.73

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.13

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