rs771028947

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000543.5(SMPD1):​c.1055A>C​(p.Glu352Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E352K) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

2
15

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.91

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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.17982897).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMPD1NM_000543.5 linkc.1055A>C p.Glu352Ala missense_variant Exon 2 of 6 ENST00000342245.9 NP_000534.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMPD1ENST00000342245.9 linkc.1055A>C p.Glu352Ala missense_variant Exon 2 of 6 1 NM_000543.5 ENSP00000340409.4

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251076
AF XY:
0.00
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000882
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461892
Hom.:
0
Cov.:
36
AF XY:
0.00000275
AC XY:
2
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.533
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
31
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Jun 30, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1055A>C (p.E352A) alteration is located in exon 2 (coding exon 2) of the SMPD1 gene. This alteration results from a A to C substitution at nucleotide position 1055, causing the glutamic acid (E) at amino acid position 352 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B Uncertain:1
Sep 07, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with alanine, which is neutral and non-polar, at codon 352 of the SMPD1 protein (p.Glu352Ala). This variant is present in population databases (rs771028947, gnomAD 0.0009%). 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: 581009). 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 not 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. -

Sphingomyelin/cholesterol lipidosis Uncertain:1
Sep 16, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Uncertain
0.020
T
BayesDel_noAF
Benign
-0.21
CADD
Benign
16
DANN
Benign
0.95
Eigen
Benign
-0.13
Eigen_PC
Benign
-0.00032
FATHMM_MKL
Uncertain
0.80
D
LIST_S2
Benign
0.79
T;T
M_CAP
Benign
0.010
T
MetaRNN
Benign
0.18
T;T
MetaSVM
Benign
-1.0
T
PhyloP100
2.9
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-0.86
N;N
REVEL
Benign
0.26
Sift
Benign
0.45
T;T
Sift4G
Benign
0.70
T;T
Vest4
0.11
MVP
0.96
MPC
0.22
ClinPred
0.15
T
GERP RS
3.8
PromoterAI
-0.0056
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.092
gMVP
0.82
Mutation Taster
=82/18
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs771028947; hg19: chr11-6413350; API