Variant 8-28716136-G-A details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001440.4(EXTL3):c.77G>A(p.Arg26His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,461,562 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R26C) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

EXTL3
NM_001440.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 10.0

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:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
EXTL3	NM_001440.4 linkuse as main transcript	c.77G>A	p.Arg26His	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.77G>A	p.Arg26His	missense_variant	3/7	1	NM_001440.4	P1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000279

AC:

AN:

251154

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135758

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000653

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461562

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727090

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000171

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000151

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 24, 2023

The c.77G>A (p.R26H) alteration is located in exon 3 (coding exon 1) of the EXTL3 gene. This alteration results from a G to A substitution at nucleotide position 77, causing the arginine (R) at amino acid position 26 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 14, 2021

This sequence change replaces arginine with histidine at codon 26 of the EXTL3 protein (p.Arg26His). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and histidine. This variant is present in population databases (rs146905864, ExAC 0.006%). This variant has not been reported in the literature in individuals affected with EXTL3-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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

0.098

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Pathogenic

0.15

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Benign

0.15

Eigen

Benign

0.027

Eigen_PC

Uncertain

0.25

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.92

M_CAP

Uncertain

0.15

MetaRNN

Uncertain

0.50

MetaSVM

Uncertain

0.16

MutationAssessor

Benign

0.0

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.67

PROVEAN

Benign

0.010

REVEL

Uncertain

0.48

Sift

Benign

0.41

Sift4G

Benign

0.44

Polyphen

0.014

Vest4

0.69

MVP

0.93

MPC

0.40

ClinPred

0.14

GERP RS

5.5

Varity_R

0.14

gMVP

0.58

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