chr19-50359055-C-A

Variant names:

• chr19-50359055-C-A
• rs2037435303
• NM_004851.3:c.991G>T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_004851.3(NAPSA):​c.991G>T​(p.Gly331Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. G331A) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NAPSA NM_004851.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.36

Genes affected

NAPSA (HGNC:13395): (napsin A aspartic peptidase) This gene encodes a member of the peptidase A1 family of aspartic proteases. The encoded preproprotein is proteolytically processed to generate an activation peptide and the mature protease. The activation peptides of aspartic proteinases function as inhibitors of the protease active site. These peptide segments, or pro-parts, are deemed important for correct folding, targeting, and control of the activation of aspartic proteinase zymogens. The encoded protease may play a role in the proteolytic processing of pulmonary surfactant protein B in the lung and may function in protein catabolism in the renal proximal tubules. This gene has been described as a marker for lung adenocarcinoma and renal cell carcinoma. [provided by RefSeq, Feb 2016]

NR1H2 (HGNC:7965): (nuclear receptor subfamily 1 group H member 2) The liver X receptors, LXRA (NR1H3; MIM 602423) and LXRB, form a subfamily of the nuclear receptor superfamily and are key regulators of macrophage function, controlling transcriptional programs involved in lipid homeostasis and inflammation. The inducible LXRA is highly expressed in liver, adrenal gland, intestine, adipose tissue, macrophages, lung, and kidney, whereas LXRB is ubiquitously expressed. Ligand-activated LXRs form obligate heterodimers with retinoid X receptors (RXRs; see MIM 180245) and regulate expression of target genes containing LXR response elements (summary by Korf et al., 2009 [PubMed 19436111]).[supplied by OMIM, Jan 2010]

LOC105372437 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.882

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NAPSA	NM_004851.3	c.991G>T	p.Gly331Trp	missense_variant	Exon 8 of 9	ENST00000253719.7	NP_004842.1
NAPSA	XM_017027512.2	c.964G>T	p.Gly322Trp	missense_variant	Exon 8 of 9		XP_016883001.1
LOC105372437	XR_007067299.1	n.367+6449C>A		intron_variant	Intron 3 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NAPSA	ENST00000253719.7	c.991G>T	p.Gly331Trp	missense_variant	Exon 8 of 9	1	NM_004851.3	ENSP00000253719.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000312 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Jan 19, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.991G>T (p.G331W) alteration is located in exon 8 (coding exon 8) of the NAPSA gene. This alteration results from a G to T substitution at nucleotide position 991, causing the glycine (G) at amino acid position 331 to be replaced by a tryptophan (W). 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	0.47
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D
Eigen	Uncertain	0.42
Eigen_PC	Benign	0.20
FATHMM_MKL	Benign	0.22	N
LIST_S2	Uncertain	0.87	D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Uncertain	0.023	D
MutationAssessor	Pathogenic	3.5	H
PrimateAI	Uncertain	0.48	T
PROVEAN	Pathogenic	-7.1	D
REVEL	Uncertain	0.39
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.77
MutPred		0.70		Gain of catalytic residue at L329 (P = 0.0077);
MVP		0.14
MPC		0.73
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.94
gMVP		0.77

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs2037435303; hg19: chr19-50862312;