Variant 8-28716123-C-T details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_001440.4(EXTL3):c.64C>T(p.Arg22Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,566 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R22H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

EXTL3
NM_001440.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.12

Variant links:

Genes affected

EXTL3 (HGNC:3518): (exostosin like glycosyltransferase 3) This gene encodes a single-pass membrane protein which functions as a glycosyltransferase. The encoded protein catalyzes the transfer of N-acetylglucosamine to glycosaminoglycan chains. This reaction is important in heparin and heparan sulfate synthesis. Alternative splicing results in the multiple transcript variants. [provided by RefSeq, Nov 2012]

EXTL3 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.797

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
EXTL3	NM_001440.4 linkuse as main transcript	c.64C>T	p.Arg22Cys	missense_variant	3/7	ENST00000220562.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
EXTL3	ENST00000220562.9 linkuse as main transcript	c.64C>T	p.Arg22Cys	missense_variant	3/7	1	NM_001440.4	P1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251032

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135730

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000939

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1461340

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727004

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.000113

Gnomad4 NFE exome

AF:

0.00000719

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.00

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:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 13, 2023

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 22 of the EXTL3 protein (p.Arg22Cys). This variant is present in population databases (rs754077651, gnomAD 0.008%). This variant has not been reported in the literature in individuals affected with EXTL3-related conditions. ClinVar contains an entry for this variant (Variation ID: 1487985). 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 EXTL3 protein function. 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

0.13

BayesDel_addAF

Pathogenic

0.25

BayesDel_noAF

Pathogenic

0.30

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.28

Eigen

Uncertain

0.24

Eigen_PC

Uncertain

0.27

FATHMM_MKL

Uncertain

0.90

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.46

MetaRNN

Pathogenic

0.80

MetaSVM

Uncertain

0.50

MutationAssessor

Benign

0.55

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.68

PROVEAN

Benign

-1.1

REVEL

Pathogenic

0.68

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.030

Polyphen

1.0

Vest4

0.85

MutPred

0.47

Loss of MoRF binding (P = 0.001);

MVP

0.96

MPC

0.65

ClinPred

0.47

GERP RS

4.7

Varity_R

0.17

gMVP

0.77

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