NM_000543.5:c.1430C>T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_000543.5(SMPD1):c.1430C>T(p.Pro477Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,614,050 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 Likely pathogenic (★★).

Frequency

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

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 7.45

Variant links:

Genes affected

SMPD1 (HGNC:11120): (sphingomyelin phosphodiesterase 1) The protein encoded by this gene is a lysosomal acid sphingomyelinase that converts sphingomyelin to ceramide. The encoded protein also has phospholipase C activity. Defects in this gene are a cause of Niemann-Pick disease type A (NPA) and Niemann-Pick disease type B (NPB). Multiple transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2010]

SMPD1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a strand (size 7) in uniprot entity ASM_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000543.5

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.974

PP5

Variant 11-6393985-C-T is Pathogenic according to our data. Variant chr11-6393985-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 189075.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-6393985-C-T is described in Lovd as [Pathogenic]. Variant chr11-6393985-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD1	NM_000543.5 link	c.1430C>T	p.Pro477Leu	missense_variant	Exon 5 of 6	ENST00000342245.9	NP_000534.3	P17405-1Q59EN6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMPD1	ENST00000342245.9 link	c.1430C>T	p.Pro477Leu	missense_variant	Exon 5 of 6	1	NM_000543.5	ENSP00000340409.4		P17405-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152162

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251486

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135918

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000867

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000205

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000207

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152162

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74322

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000689

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type A

Pathogenic:4

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 26, 2014

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Sep 26, 2019

Biochemical Molecular Genetic Laboratory, King Abdulaziz Medical City

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jun 21, 2023

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Criteria applied: PM3_VSTR,PM2_SUP,PP3,PP4 -

Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B

Pathogenic:2

Jun 07, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 477 of the SMPD1 protein (p.Pro477Leu). This variant is present in population databases (rs753508874, gnomAD 0.009%). This missense change has been observed in individual(s) with Niemann-Pick disease (PMID: 12556236, 12712061, 15221801, 17011332, 22818240). This variant is also known as P475L. ClinVar contains an entry for this variant (Variation ID: 189075). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SMPD1 protein function with a positive predictive value of 95%. This variant disrupts the p.Pro477 amino acid residue in SMPD1. Other variant(s) that disrupt this residue have been observed in individuals with SMPD1-related conditions (PMID: 27338287), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:2

Aug 10, 2021

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 20, 2020

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); Missense variants in this gene are often considered pathogenic (Stenson et al., 2014); 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: 17011332, 22818240, 12369017, 12556236, 15221801, 12712061, 30202406, 30548430) -

Sphingomyelin/cholesterol lipidosis

Pathogenic:1

Jan 22, 2020

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Pro477Leu variant in SMPD1 (also known as p.Pro475Leu due to a difference in cDNA numbering) has been reported in at least 9 individuals with Niemann-Pick disease, segregated with disease in 4 affected relatives from 2 families (PMID: 15221801, 12712061, 15234149, 17011332, 22818240), and has been identified in 0.008% (3/35438) of Latino chromosomes, 0.003% (1/30614) of South Asian chromosomes, and 0.002% (2/129190) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs753508874). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (VariationID: 189075) as likely pathogenic by Counsyl and GeneDx. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The phenotype of individuals homozygous and compound heterozygous for this variant is highly specific for Niemann-Pick disease based on acid sphingomyelinase activity being <10% of normal, consistent with disease (PMID: 22818240). In summary, this variant meets criteria to be classified as pathogenic for Niemann-Pick disease in an autosomal recessive manner based on its presence in combination with reported pathogenic variants, its presence in individuals with a phenotype highly specific for Niemann-Pick disease, and co-segregation with disease. ACMG/AMP Criteria applied: PM3_very-strong, PM2, PP3, PP4, PP1 (Richards 2015). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.74

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.58

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.56

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

D;D

M_CAP

Pathogenic

0.52

MetaRNN

Pathogenic

0.97

D;D

MetaSVM

Uncertain

0.30

PrimateAI

Uncertain

0.67

PROVEAN

Pathogenic

-6.6

D;D

REVEL

Pathogenic

0.94

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.0040

D;D

Vest4

0.95

MVP

0.99

MPC

0.81

ClinPred

1.0

GERP RS

4.7

Varity_R

0.74

gMVP

0.93

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over