Variant chr8-28717074-C-T details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_001440.4(EXTL3):c.1015C>T(p.Arg339Trp) variant causes a missense change. The variant allele was found at a frequency of 0.00000616 in 1,461,884 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 (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

EXTL3
NM_001440.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 3.78

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:

EXTL3 (HGNC:):

EXTL3 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.965

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
EXTL3	NM_001440.4 linkuse as main transcript	c.1015C>T	p.Arg339Trp	missense_variant	3/7	ENST00000220562.9	NP_001431.1	O43909A0A384NPY9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
EXTL3	ENST00000220562.9 linkuse as main transcript	c.1015C>T	p.Arg339Trp	missense_variant	3/7	1	NM_001440.4	ENSP00000220562.4		O43909

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251158

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135746

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.00

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:

0.00000629

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Immunoskeletal dysplasia with neurodevelopmental abnormalities

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Apr 05, 2017

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 09, 2022

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 339 of the EXTL3 protein (p.Arg339Trp). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of EXTL3 deficiency (PMID: 28148688). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 417796). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.54

BayesDel_noAF

Pathogenic

0.54

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.97

Eigen

Pathogenic

0.70

Eigen_PC

Pathogenic

0.68

FATHMM_MKL

Uncertain

0.97

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.61

MetaRNN

Pathogenic

0.96

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.7

PrimateAI

Pathogenic

0.92

PROVEAN

Pathogenic

-7.8

REVEL

Pathogenic

0.86

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.98

MutPred

0.79

Gain of sheet (P = 0.0011);

MVP

0.99

MPC

1.1

ClinPred

1.0

GERP RS

5.5

Varity_R

0.91

gMVP

0.92

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