rs80358261

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_006432.5(NPC2):​c.115G>A​(p.Val39Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000262 in 1,602,146 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 (★★). Synonymous variant affecting the same amino acid position (i.e. V39V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

NPC2
NM_006432.5 missense

Scores

9
9
1

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:2O:1

Conservation

PhyloP100: 4.27

Publications

16 publications found
Variant links:
Genes affected
NPC2 (HGNC:14537): (NPC intracellular cholesterol transporter 2) This gene encodes a protein containing a lipid recognition domain. The encoded protein may function in regulating the transport of cholesterol through the late endosomal/lysosomal system. Mutations in this gene have been associated with Niemann-Pick disease, type C2 and frontal lobe atrophy. [provided by RefSeq, Jul 2008]
NPC2 Gene-Disease associations (from GenCC):
  • Niemann-Pick disease, type C2
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, G2P, Genomics England PanelApp, Laboratory for Molecular Medicine, ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • Niemann-Pick disease type C, adult neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, juvenile neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, late infantile neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, severe early infantile neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, severe perinatal form
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a disulfide_bond (size 113) in uniprot entity NPC2_HUMAN there are 6 pathogenic changes around while only 1 benign (86%) in NM_006432.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.792

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NPC2NM_006432.5 linkc.115G>A p.Val39Met missense_variant Exon 2 of 5 ENST00000555619.6 NP_006423.1
NPC2NM_001363688.1 linkc.115G>A p.Val39Met missense_variant Exon 2 of 4 NP_001350617.1
NPC2NM_001375440.1 linkc.115G>A p.Val39Met missense_variant Exon 2 of 4 NP_001362369.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NPC2ENST00000555619.6 linkc.115G>A p.Val39Met missense_variant Exon 2 of 5 1 NM_006432.5 ENSP00000451112.2 P61916-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152156
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000174
AC:
4
AN:
229918
AF XY:
0.0000243
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:
0.0000389
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000276
AC:
40
AN:
1449990
Hom.:
0
Cov.:
31
AF XY:
0.0000264
AC XY:
19
AN XY:
719790
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33390
American (AMR)
AF:
0.00
AC:
0
AN:
42998
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25748
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39578
South Asian (SAS)
AF:
0.00
AC:
0
AN:
83722
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52728
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.0000353
AC:
39
AN:
1106082
Other (OTH)
AF:
0.00
AC:
0
AN:
59986
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.459
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.0000131
AC:
2
AN:
152156
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41436
American (AMR)
AF:
0.0000655
AC:
1
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000262
Hom.:
0
Bravo
AF:
0.00000378
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000825
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:2Other:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Niemann-Pick disease, type C2 Pathogenic:1Uncertain:1Other:1
Dec 01, 2002
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Sep 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 39 of the NPC2 protein (p.Val39Met). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with Niemann–Pick disease type C (PMID: 12447927). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 8483). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change does not substantially affect NPC2 function (PMID: 15937921). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

NPC2-related disorder Uncertain:1
Jan 30, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The NPC2 c.115G>A variant is predicted to result in the amino acid substitution p.Val39Met. This variant was reported in the homozygous state in two sisters who presented in middle age with dementia and hallucinations (Klunemann et al. 2002. PubMed ID: 12447927). In functional studies, the p.Val39Met substitution was reported to result in functionally normal NPC2 protein (Chikh et al. 2005. PubMed ID: 15937921). This variant is reported in 0.0039% of alleles in individuals of European (Non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.73
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.37
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.63
D;.;D;.;.;.;T
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Uncertain
0.92
D;D;D;D;D;D;D
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.79
D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.91
D
MutationAssessor
Pathogenic
3.2
.;M;M;.;.;.;.
PhyloP100
4.3
PrimateAI
Uncertain
0.52
T
PROVEAN
Uncertain
-2.6
D;D;D;D;D;D;D
REVEL
Pathogenic
0.80
Sift
Uncertain
0.0010
D;D;D;D;D;D;D
Sift4G
Uncertain
0.0020
D;D;D;D;.;D;.
Polyphen
1.0
.;.;D;.;.;.;.
Vest4
0.84
MVP
0.99
MPC
1.3
ClinPred
0.97
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.91
gMVP
0.78
Mutation Taster
=1/99
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs80358261; hg19: chr14-74953107; COSMIC: COSV104587384; COSMIC: COSV104587384; API