rs113371321

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM5PP2PP3

The NM_000271.5(NPC1):​c.3560C>T​(p.Ala1187Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000459 in 1,613,908 control chromosomes in the GnomAD database, including 1 homozygotes. 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. A1187T) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000044 ( 1 hom. )

Consequence

NPC1
NM_000271.5 missense

Scores

6
8
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 9.99

Publications

9 publications found
Variant links:
Genes affected
NPC1 (HGNC:7897): (NPC intracellular cholesterol transporter 1) This gene encodes a large protein that resides in the limiting membrane of endosomes and lysosomes and mediates intracellular cholesterol trafficking via binding of cholesterol to its N-terminal domain. It is predicted to have a cytoplasmic C-terminus, 13 transmembrane domains, and 3 large loops in the lumen of the endosome - the last loop being at the N-terminus. This protein transports low-density lipoproteins to late endosomal/lysosomal compartments where they are hydrolized and released as free cholesterol. Defects in this gene cause Niemann-Pick type C disease, a rare autosomal recessive neurodegenerative disorder characterized by over accumulation of cholesterol and glycosphingolipids in late endosomal/lysosomal compartments.[provided by RefSeq, Aug 2009]
NPC1 Gene-Disease associations (from GenCC):
  • Niemann-Pick disease, type C1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Myriad Women’s Health
  • 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: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000271.5
PM5
Other missense variant is known to change same aminoacid residue: Variant chr18-23534478-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 499348.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 171 curated pathogenic missense variants (we use a threshold of 10). The gene has 18 curated benign missense variants. Gene score misZ: 1.0917 (below the threshold of 3.09). Trascript score misZ: 1.706 (below the threshold of 3.09). GenCC associations: The gene is linked to Niemann-Pick disease, type C1, Niemann-Pick disease type C, severe early infantile neurologic onset, Niemann-Pick disease type C, late infantile neurologic onset, Niemann-Pick disease type C, adult neurologic onset, Niemann-Pick disease type C, juvenile neurologic onset, Niemann-Pick disease type C, severe perinatal form.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.791

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NPC1NM_000271.5 linkc.3560C>T p.Ala1187Val missense_variant Exon 23 of 25 ENST00000269228.10 NP_000262.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NPC1ENST00000269228.10 linkc.3560C>T p.Ala1187Val missense_variant Exon 23 of 25 1 NM_000271.5 ENSP00000269228.4 O15118-1

Frequencies

GnomAD3 genomes
AF:
0.0000591
AC:
9
AN:
152248
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.000413
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000119
AC:
30
AN:
251064
AF XY:
0.000133
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000463
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.000489
GnomAD4 exome
AF:
0.0000445
AC:
65
AN:
1461542
Hom.:
1
Cov.:
30
AF XY:
0.0000591
AC XY:
43
AN XY:
727080
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.000514
AC:
23
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.0000756
AC:
3
AN:
39698
South Asian (SAS)
AF:
0.000197
AC:
17
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53132
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1111968
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
4
8
13
17
21
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:
0.0000591
AC:
9
AN:
152366
Hom.:
0
Cov.:
33
AF XY:
0.0000805
AC XY:
6
AN XY:
74502
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41590
American (AMR)
AF:
0.000196
AC:
3
AN:
15314
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5182
South Asian (SAS)
AF:
0.000414
AC:
2
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68028
Other (OTH)
AF:
0.000473
AC:
1
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000610
Hom.:
0
Bravo
AF:
0.0000642
ExAC
AF:
0.000115
AC:
14
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1 Uncertain:4
Feb 08, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jan 05, 2018
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Sep 07, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1187 of the NPC1 protein (p.Ala1187Val). This variant is present in population databases (rs113371321, gnomAD 0.04%). This missense change has been observed in individual(s) with clinical features of Niemann-Pick Type C (PMID: 19252935, 31130284, 32138288). ClinVar contains an entry for this variant (Variation ID: 556002). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant disrupts the p.Ala1187 amino acid residue in NPC1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26981555; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -

Sep 06, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:2
Sep 29, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 25, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in adults with psychotic symptoms in published literature (Fancello et al., 2009; Sriretnakumar et al., 2019); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34426522, 19252935, 32138288, 31130284, 30556376, 34670123) -

not specified Uncertain:1
Oct 18, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: NPC1 c.3560C>T (p.Ala1187Val) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00012 in 251064 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in NPC1 causing Niemann-Pick Disease Type C (0.00012 vs 0.0027), allowing no conclusion about variant significance. c.3560C>T has been reported in the literature in individuals affected with clinical features of Niemann-Pick Type C (examples: Fancello_2009, Monies_2019, Sriretnakumar_2019, Dardis_2020, Chen_2022). These report(s) do not provide unequivocal conclusions about association of the variant with Niemann-Pick Disease Type C. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 30556376, 35861376, 32138288, 19252935, 31130284, 33138774). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Inborn genetic diseases Uncertain:1
Oct 25, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.3560C>T (p.A1187V) alteration is located in exon 23 (coding exon 23) of the NPC1 gene. This alteration results from a C to T substitution at nucleotide position 3560, causing the alanine (A) at amino acid position 1187 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

NPC1-related disorder Uncertain:1
Sep 09, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The NPC1 c.3560C>T variant is predicted to result in the amino acid substitution p.Ala1187Val. This variant has been reported in an individual with Niemann-Pick disease, type C (NPC) (Fancello et al. 2009. PubMed ID: 19252935) and has been reported in the homozygous state in an infant with fine and gross motor delay, speech delay, intellectual disability, white matter changes, and spasticity (Table S1, Monies et al. 2019. PubMed ID: 31130284). It has been reported in the homozygous state in a boy with infantile onset global developmental delay, microcephaly and dysmorphic features, biochemical studies did not support pathogenicity (Almenabawy et al. 2024. PubMed ID: 38549495). An alternate nucleotide change, p.Ala1187Gly, has been reported in the compound heterozygous state in an individual with NPC (Table S1, Reunert et al. 2015. PubMed ID: 26981555). This variant is reported in 0.045% of alleles in individuals of Latino 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
Benign
0.25
BayesDel_addAF
Pathogenic
0.16
D
BayesDel_noAF
Pathogenic
0.33
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.77
D
Eigen
Uncertain
0.63
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Uncertain
0.12
D
MetaRNN
Pathogenic
0.79
D
MetaSVM
Uncertain
0.30
D
MutationAssessor
Benign
2.0
M
PhyloP100
10
PrimateAI
Uncertain
0.64
T
PROVEAN
Uncertain
-3.2
D
REVEL
Pathogenic
0.67
Sift
Benign
0.13
T
Sift4G
Benign
0.091
T
Polyphen
1.0
D
Vest4
0.85
MVP
0.90
MPC
0.91
ClinPred
0.26
T
GERP RS
5.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.59
gMVP
0.81
Mutation Taster
=2/98
disease causing

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: rs113371321; hg19: chr18-21114441; COSMIC: COSV52573233; COSMIC: COSV52573233; API