Genetic Variant NAPB:p.Met193Val (chr20-23381302-T-C) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_022080.3(NAPB):c.577A>G(p.Met193Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000107 in 1,590,082 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

NAPB
NM_022080.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.93

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 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NAPB	NM_022080.3 link	c.577A>G	p.Met193Val	missense_variant	Exon 8 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.577A>G	p.Met193Val	missense_variant	Exon 8 of 11	1	NM_022080.3	ENSP00000366225.4		Q9H115-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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

GnomAD2 exomes

AF:

0.00000865

AC:

AN:

231134

AF XY:

0.00

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000189

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000111

AC:

AN:

1437856

Hom.:

Cov.:

AF XY:

0.00000841

AC XY:

AN XY:

713284

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32460

American (AMR)

AF:

0.00

AC:

AN:

41226

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25088

East Asian (EAS)

AF:

0.00

AC:

AN:

38604

South Asian (SAS)

AF:

0.0000120

AC:

AN:

83264

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52952

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5666

European-Non Finnish (NFE)

AF:

0.0000136

AC:

AN:

1099220

Other (OTH)

AF:

0.00

AC:

AN:

59376

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.472

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74382

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41474

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Jun 06, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.577A>G (p.M193V) alteration is located in exon 8 (coding exon 8) of the NAPB gene. This alteration results from a A to G substitution at nucleotide position 577, causing the methionine (M) at amino acid position 193 to be replaced by a valine (V). 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

Benign

0.12

BayesDel_addAF

Uncertain

0.041

BayesDel_noAF

Benign

-0.16

CADD

Uncertain

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.12

.;.;.;T

Eigen

Benign

0.15

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.93

D;D;D;D

M_CAP

Benign

0.0095

MetaRNN

Uncertain

0.52

D;D;D;D

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.5

.;.;.;L

PhyloP100

7.9

PrimateAI

Uncertain

0.74

PROVEAN

Benign

-1.7

N;N;.;N

REVEL

Benign

0.17

Sift

Benign

0.15

T;T;.;D

Sift4G

Uncertain

0.054

T;T;T;T

Polyphen

0.20

.;.;.;B

Vest4

0.71

MVP

0.51

MPC

0.58

ClinPred

0.36

GERP RS

5.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.38

gMVP

0.50

Mutation Taster

=62/38

polymorphism

(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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chr20-23381302-T-C

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