Genetic Variant NM_000271.5:c.2842G>C (chr18-23539424-C-G) – ACMG Classification: Pathogenic (13 pts)

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PS1_ModeratePM1PM2PM5PP3_StrongPP5

The NM_000271.5(NPC1):c.2842G>C(p.Asp948His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,492 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 Lovd as Pathogenic (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D948Y) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

NPC1
NM_000271.5 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 7.75

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 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 13 ACMG points.

PS1

Transcript NM_000271.5 (NPC1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt

PM1

In a helix (size 7) in uniprot entity NPC1_HUMAN there are 10 pathogenic changes around while only 0 benign (100%) in NM_000271.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.989

PP5

Variant 18-23539424-C-G is Pathogenic according to our data. Variant chr18-23539424-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPC1	NM_000271.5 link	c.2842G>C	p.Asp948His	missense_variant	Exon 19 of 25	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
NPC1	ENST00000269228.10 link	c.2842G>C	p.Asp948His	missense_variant	Exon 19 of 25	1	NM_000271.5	ENSP00000269228.4	O15118-1
NPC1	ENST00000591051.1 link	c.1918G>C	p.Asp640His	missense_variant	Exon 12 of 18	2		ENSP00000467636.1	K7EQ23
NPC1	ENST00000591075.1 link	n.475G>C		non_coding_transcript_exon_variant	Exon 1 of 3	4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461492

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727002

show subpopulations

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.94

BayesDel_addAF

Pathogenic

0.52

BayesDel_noAF

Pathogenic

0.51

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.82

Eigen

Pathogenic

0.86

Eigen_PC

Pathogenic

0.79

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.97

M_CAP

Pathogenic

0.34

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

0.99

MutationAssessor

Pathogenic

3.4

PrimateAI

Uncertain

0.65

PROVEAN

Pathogenic

-6.1

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0090

Polyphen

1.0

Vest4

0.94

MutPred

0.91

Loss of stability (P = 0.0613);

MVP

0.98

MPC

1.0

ClinPred

0.99

GERP RS

5.3

Varity_R

0.81

gMVP

0.91

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

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over