Variant rs750779804 details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PS1PM1PM2PP5_Very_Strong

The NM_000543.5(SMPD1):c.748A>C(p.Ser250Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,460,856 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin Lovd.

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 3.24

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:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PS1

Transcript NM_000543.5 (SMPD1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in Lovd

PM1

In a mutagenesis_site No effect on sphingomyelin phosphodiesterase activity. No effect on endolysosome location. No effect on phosphorylation by PRKCD. (size 0) in uniprot entity ASM_HUMAN

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 11-6391813-A-C is Pathogenic according to our data. Variant chr11-6391813-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 371576.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMPD1	NM_000543.5 linkuse as main transcript	c.748A>C	p.Ser250Arg	missense_variant	2/6	ENST00000342245.9	NP_000534.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMPD1	ENST00000342245.9 linkuse as main transcript	c.748A>C	p.Ser250Arg	missense_variant	2/6	1	NM_000543.5	ENSP00000340409	P3	P17405-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000803

AC:

AN:

249078

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135122

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 SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000885

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1460856

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

726794

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:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000108

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.00209

Hom.:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

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

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 03, 2020	For these reasons, this variant has been classified as Pathogenic. This variant has been reported to affect SMPD1 protein function (PMID: 16642440). This variant has been observed in individual(s) with Niemann-Pick disease (PMID: 12556236, 15877209, 16642440, 23430884). This variant is also known as g.1208A>C, c.742A>C (S248R) in the literature. ClinVar contains an entry for this variant (Variation ID: 371576). This variant is present in population databases (rs750779804, ExAC 0.006%). This sequence change replaces serine with arginine at codon 250 of the SMPD1 protein (p.Ser250Arg). The serine residue is moderately conserved and there is a moderate physicochemical difference between serine and arginine. -
Pathogenic, criteria provided, single submitter	clinical testing	Centogene AG - the Rare Disease Company	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Jul 22, 2021	- -

Niemann-Pick disease, type A

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 13, 2024	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 16, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Oct 24, 2016	- -

not specified

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Feb 09, 2018

Variant summary: SMPD1 c.748A>C (p.Ser250Arg) results in a non-conservative amino acid change located in ApaH type Calcineurin-like phosphoesterase domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.2e-06 in 244428 control chromosomes in gnomAD. This frequency is not significantly higher than expected for a pathogenic variant in SMPD1 causing Niemann-Pick Disease (1.7e-05 vs 0.0022), allowing no conclusion about variant significance. c.748A>C has been reported in the literature in individuals affected with Niemann-Pick Disease Type A and B (Hollak_2012, Zhang_2013, Toth_2011, Diggelen_2005). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity (Hollak_2012). One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Sphingomyelin/cholesterol lipidosis

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

curation

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

Jan 22, 2020

The p.Ser250Arg variant in SMPD1 (also known as p.Ser248Arg due to a difference in cDNA numbering) has been reported in at least 6 individuals with Niemann-Pick disease (PMID: 16642440, 15877209, 22818240, 14681755, 23430884, 23356216) and has been identified in 0.003% (1/30578) of South Asian chromosomes and 0.001% (1/112970) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs750779804). 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: 371576) as likely pathogenic by Counsyl and as pathogenic by Integrated Genetics. In vitro functional studies provide some evidence that the p.Ser250Arg variant may impact protein function (PMID: 16642440). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. The presence of this variant in 1 affected homozygote and in combination with reported pathogenic and likely pathogenic variants in individuals with Niemann-Pick disease increases the likelihood that the p.Ser250Arg variant is pathogenic (VariationID: 551367, 2994; PMID: 16642440, 15877209, 22818240, 14681755, 23430884). The phenotype of an individual compound heterozygous for this variant is highly specific for Niemann-Pick disease based on acid sphingomyselinase activity being <10% of normal, consistent with disease (PMID: 15877209, 22818240, 23356216). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic. ACMG/AMP Criteria applied: PM3_strong, PM2, PS3_moderate, PP4 (Richards 2015). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.58

BayesDel_addAF

Pathogenic

0.27

BayesDel_noAF

Pathogenic

0.25

CADD

Benign

DANN

Benign

0.93

Eigen

Benign

-0.36

Eigen_PC

Benign

-0.15

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.86

D;D

M_CAP

Uncertain

0.087

MetaRNN

Uncertain

0.68

D;D

MetaSVM

Uncertain

-0.21

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.71

PROVEAN

Benign

0.65

N;N

REVEL

Uncertain

0.52

Sift

Benign

1.0

T;T

Sift4G

Benign

0.78

T;T

Vest4

0.91

MVP

0.98

MPC

0.31

ClinPred

0.36

GERP RS

3.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.23

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

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