11-6394482-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_000543.5(SMPD1):​c.1771C>T​(p.Arg591Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,613,780 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

9
6
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 3.64
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.91

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMPD1NM_000543.5 linkc.1771C>T p.Arg591Cys 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
SMPD1ENST00000342245.9 linkc.1771C>T p.Arg591Cys missense_variant Exon 6 of 6 1 NM_000543.5 ENSP00000340409.4 P17405-1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152204
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000121
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:
0.000478
GnomAD3 exomes
AF:
0.0000119
AC:
3
AN:
251088
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135738
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:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461576
Hom.:
0
Cov.:
34
AF XY:
0.0000138
AC XY:
10
AN XY:
727100
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000756
Gnomad4 SAS exome
AF:
0.0000348
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000360
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000460
AC:
7
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74352
show subpopulations
Gnomad4 AFR
AF:
0.000121
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:
0.0000147
Gnomad4 OTH
AF:
0.000478
Alfa
AF:
0.0000558
Hom.:
0
Bravo
AF:
0.0000793
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.000164
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B Uncertain:2
Sep 17, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine with cysteine at codon 591 of the SMPD1 protein (p.Arg591Cys). The arginine residue is moderately conserved and there is a large physicochemical difference between arginine and cysteine. This variant is present in population databases (rs375570126, ExAC 0.002%). This variant has not been reported in the literature in individuals affected with SMPD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 550895). 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. 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. -

Jan 14, 2022
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Inborn genetic diseases Uncertain:1
Sep 02, 2021
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.1771C>T (p.R591C) alteration is located in exon 6 (coding exon 6) of the SMPD1 gene. This alteration results from a C to T substitution at nucleotide position 1771, causing the arginine (R) at amino acid position 591 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Niemann-Pick disease, type A Uncertain:1
Mar 01, 2017
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.31
BayesDel_addAF
Pathogenic
0.29
D
BayesDel_noAF
Pathogenic
0.20
CADD
Pathogenic
26
DANN
Pathogenic
1.0
Eigen
Uncertain
0.63
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Pathogenic
0.51
D
MetaRNN
Pathogenic
0.91
D;D
MetaSVM
Uncertain
0.59
D
PrimateAI
Uncertain
0.61
T
PROVEAN
Pathogenic
-4.8
D;D
REVEL
Pathogenic
0.72
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0010
D;D
Vest4
0.72
MVP
0.97
MPC
0.85
ClinPred
0.98
D
GERP RS
5.4
Varity_R
0.63
gMVP
0.68

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.

Other links and lift over

dbSNP: rs375570126; hg19: chr11-6415712; COSMIC: COSV104599146; COSMIC: COSV104599146; API