18-10546337-C-T

Position:

• chr18-10546337-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_003826.3(NAPG):​c.518C>T​(p.Ala173Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000841 in 1,427,196 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: 32)
  • Exomes 𝑓: 0.0000084 (0 hom.)
• Consequence: NAPG NM_003826.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.41

Genes affected

NAPG (HGNC:7642): (NSF attachment protein gamma) This gene encodes soluble NSF attachment protein gamma. The soluble NSF attachment proteins (SNAPs) enable N-ethyl-maleimide-sensitive fusion protein (NSF) to bind to target membranes. NSF and SNAPs appear to be general components of the intracellular membrane fusion apparatus, and their action at specific sites of fusion must be controlled by SNAP receptors particular to the membranes being fused. The product of this gene mediates platelet exocytosis and controls the membrane fusion events of this process.[provided by RefSeq, Dec 2008]

ACMG classification

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, 0.943

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NAPG	NM_003826.3	c.518C>T	p.Ala173Val	missense_variant	9/12	ENST00000322897.11
NAPG	XM_011525754.3	c.698C>T	p.Ala233Val	missense_variant	10/13
NAPG	XM_011525756.3	c.272C>T	p.Ala91Val	missense_variant	7/10
NAPG	XM_017026063.3	c.263C>T	p.Ala88Val	missense_variant	5/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NAPG	ENST00000322897.11	c.518C>T	p.Ala173Val	missense_variant	9/12	1	NM_003826.3	P1
NAPG	ENST00000583367.1	n.898C>T		non_coding_transcript_exon_variant	4/7	2
NAPG	ENST00000580224.5	c.*381C>T		3_prime_UTR_variant, NMD_transcript_variant	8/11	2
NAPG	ENST00000580483.5	c.*259C>T		3_prime_UTR_variant, NMD_transcript_variant	5/8	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000841 AC: 12 AN: 1427196 Hom.: 0 Cov.: 27 AF XY: 0.00000565 AC XY: 4 AN XY: 708532

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000110

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 15, 2023

The c.518C>T (p.A173V) alteration is located in exon 9 (coding exon 9) of the NAPG gene. This alteration results from a C to T substitution at nucleotide position 518, causing the alanine (A) at amino acid position 173 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	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.27	T
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.6	M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.014	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.79		Gain of MoRF binding (P = 0.0974);
MVP		0.99
MPC		0.54
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.67
gMVP		0.76

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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

Other links and lift over

dbSNP: rs956039626; hg19: chr18-10546334; COSMIC: COSV59797236;