chr20-23390260-A-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_022080.3(NAPB):c.425T>C(p.Ile142Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,258 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. I142V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

NAPB
NM_022080.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.32

Publications

0 publications found

Variant links:

Genes affected

NAPB (HGNC:15751): (NSF attachment protein beta) This gene encodes a member of the soluble N-ethyl-maleimide-sensitive fusion attachment protein (SNAP) family. SNAP proteins play a critical role in the docking and fusion of vesicles to target membranes as part of the 20S NSF-SNAP-SNARE complex. This gene encodes the SNAP beta isoform which has been shown to be preferentially expressed in brain tissue. The encoded protein also interacts with the GluR2 α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit C-terminus and may play a role as a chaperone in the molecular processing of the AMPA receptor. [provided by RefSeq, Mar 2017]

NAPB Gene-Disease associations (from GenCC):

developmental and epileptic encephalopathy 107
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P

NAPB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.812

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NAPB	NM_022080.3 link	c.425T>C	p.Ile142Thr	missense_variant	Exon 6 of 11	ENST00000377026.4	NP_071363.1	Q9H115-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NAPB	ENST00000377026.4 link	c.425T>C	p.Ile142Thr	missense_variant	Exon 6 of 11	1	NM_022080.3	ENSP00000366225.4		Q9H115-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152258

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

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

GnomAD2 exomes

AF:

0.00000399

AC:

AN:

250786

AF XY:

0.00000738

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1457358

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

725296

African (AFR)

AF:

0.00

AC:

AN:

33406

American (AMR)

AF:

0.00

AC:

AN:

44684

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26108

East Asian (EAS)

AF:

0.00

AC:

AN:

39662

South Asian (SAS)

AF:

0.00

AC:

AN:

86068

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5756

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1108040

Other (OTH)

AF:

0.00

AC:

AN:

60236

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152258

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74398

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41464

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000192

AC:

AN:

5208

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10630

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Mar 08, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.425T>C (p.I142T) alteration is located in exon 6 (coding exon 6) of the NAPB gene. This alteration results from a T to C substitution at nucleotide position 425, causing the isoleucine (I) at amino acid position 142 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.38

BayesDel_addAF

Pathogenic

0.16

BayesDel_noAF

Pathogenic

0.17

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.32

.;.;.;T

Eigen

Uncertain

0.56

Eigen_PC

Uncertain

0.57

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.93

D;D;D;D

M_CAP

Benign

0.063

MetaRNN

Pathogenic

0.81

D;D;D;D

MetaSVM

Benign

-0.62

MutationAssessor

Pathogenic

2.9

.;.;.;M

PhyloP100

9.3

PrimateAI

Pathogenic

0.87

PROVEAN

Uncertain

-3.6

D;D;.;D

REVEL

Uncertain

0.59

Sift

Benign

0.034

D;D;.;D

Sift4G

Uncertain

0.013

D;D;D;D

Polyphen

0.53

.;.;.;P

Vest4

0.79

MutPred

0.69

.;.;.;Gain of disorder (P = 0.0256);

MVP

0.43

MPC

0.73

ClinPred

0.92

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.45

gMVP

0.63

Mutation Taster

=30/70

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

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chr20-23390260-A-G

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over