dbSNP rs770842408: EXTL3:p.Asn657Thr (chr8-28718029-A-C) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_001440.4(EXTL3):c.1970A>C(p.Asn657Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N657S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

EXTL3
NM_001440.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 9.25

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

immunoskeletal dysplasia with neurodevelopmental abnormalities
Inheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)

EXTL3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.874

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
EXTL3	NM_001440.4 link	c.1970A>C	p.Asn657Thr	missense_variant	Exon 3 of 7	ENST00000220562.9	NP_001431.1	O43909A0A384NPY9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
EXTL3	ENST00000220562.9 link	c.1970A>C	p.Asn657Thr	missense_variant	Exon 3 of 7	1	NM_001440.4	ENSP00000220562.4		O43909

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461894

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727248

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.55

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.26

T;D

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.89

D;D

M_CAP

Pathogenic

0.44

MetaRNN

Pathogenic

0.87

D;D

MetaSVM

Pathogenic

0.98

MutationAssessor

Uncertain

2.4

.;M

PhyloP100

9.2

PrimateAI

Pathogenic

0.85

PROVEAN

Pathogenic

-4.9

D;D

REVEL

Pathogenic

0.71

Sift

Uncertain

0.0050

D;D

Sift4G

Benign

0.27

T;D

Polyphen

1.0

.;D

Vest4

0.85

MutPred

0.33

.;Loss of helix (P = 0.0626);

MVP

0.97

MPC

0.54

ClinPred

0.99

GERP RS

5.7

PromoterAI

0.022

Neutral

(source)

Varity_R

0.76

gMVP

0.84

Mutation Taster

=14/86

disease causing

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over