rs1554935669

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM1PM2PM5PP3PP5_Very_Strong

The NM_000543.5(SMPD1):c.1730A>G(p.His577Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,614,054 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H577L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6U:1

Conservation

PhyloP100: 7.13

Publications

1 publications found

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 Gene-Disease associations (from GenCC):

acid sphingomyelinase deficiency
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
Niemann-Pick disease
Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
Niemann-Pick disease type A
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
Niemann-Pick disease type B
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)

SMPD1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000543.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr11-6394441-A-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3759148.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.748

PP5

Variant 11-6394441-A-G is Pathogenic according to our data. Variant chr11-6394441-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 550112.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD1	NM_000543.5 link	c.1730A>G	p.His577Arg	missense_variant	Exon 6 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.1730A>G	p.His577Arg	missense_variant	Exon 6 of 6	1	NM_000543.5	ENSP00000340409.4		P17405-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152166

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74334

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41444

American (AMR)

AF:

0.00

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68012

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type A

Pathogenic:2Uncertain:1

May 04, 2022

Mendelics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dec 29, 2016

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. -

Mar 29, 2024

Baylor Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

Pathogenic:2

Apr 25, 2021

Diagnostics Division, CENTRE FOR DNA FINGERPRINTING AND DIAGNOSTICS

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

- -

Aug 16, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense change has been observed in individual(s) with Niemann-Pick disease (PMID: 20386867, 34273913). This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 577 of the SMPD1 protein (p.His577Arg). This variant is not present in population databases (gnomAD no frequency). ClinVar contains an entry for this variant (Variation ID: 550112). 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. Experimental studies have shown that this missense change affects SMPD1 function (PMID: 20386867). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. This variant disrupts the p.His577 amino acid residue in SMPD1. Other variant(s) that disrupt this residue have been observed in individuals with SMPD1-related conditions (PMID: 12712061, 20386867, 26499107), 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:1

Nov 03, 2022

Revvity Omics, Revvity

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sphingomyelin/cholesterol lipidosis

Pathogenic:1

Aug 28, 2023

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

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: SMPD1 c.1730A>G (p.His577Arg) results in a non-conservative amino acid change located in the Sphingomyelin phosphodiesterase, C-terminal domain (IPR045473) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251448 control chromosomes (gnomAD). c.1730A>G has been reported in the literature in compound heterozygous and homozygous individuals affected with Niemann-Pick Disease (Desnick_2010, Deshpande_2021). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function and p.H577R had less than 1% of expressed wild-type activity (Desnick_2010). The following publications have been ascertained in the context of this evaluation (PMID: 34273913, 20386867, 27435900). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified this variant as uncertain significance (n=1, likely pathogenic (n=3) and pathogenic (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Pathogenic

0.38

BayesDel_noAF

Pathogenic

0.31

CADD

Benign

(source)

DANN

Uncertain

0.99

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.50

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.86

D;D

M_CAP

Benign

0.064

MetaRNN

Pathogenic

0.75

D;D

MetaSVM

Benign

-0.31

PhyloP100

7.1

PrimateAI

Uncertain

0.69

PROVEAN

Uncertain

-2.9

D;D

REVEL

Pathogenic

0.80

Sift

Benign

0.27

T;T

Sift4G

Benign

0.43

T;T

Vest4

0.72

MVP

0.99

MPC

0.85

ClinPred

0.89

GERP RS

5.4

Varity_R

0.55

gMVP

0.80

Mutation Taster

=5/95

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over