rs35785620

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4_Moderate

The NM_000543.5(SMPD1):​c.1763C>A​(p.Thr588Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,614,034 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 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. T588M) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

17

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.388

Publications

5 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.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000543.5
BP4
Computational evidence support a benign effect (MetaRNN=0.08183572).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMPD1NM_000543.5 linkc.1763C>A p.Thr588Lys 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.1763C>A p.Thr588Lys missense_variant Exon 6 of 6 1 NM_000543.5 ENSP00000340409.4 P17405-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152212
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251210
AF XY:
0.00000736
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000116
AC:
17
AN:
1461704
Hom.:
0
Cov.:
34
AF XY:
0.00000825
AC XY:
6
AN XY:
727164
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000335
AC:
15
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:
53250
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111996
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000656
AC:
1
AN:
152330
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74482
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41582
American (AMR)
AF:
0.0000653
AC:
1
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
25
Bravo
AF:
0.0000189
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B Uncertain:1
Aug 09, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with lysine, which is basic and polar, at codon 588 of the SMPD1 protein (p.Thr588Lys). This variant is present in population databases (rs35785620, gnomAD 0.009%). This variant has not been reported in the literature in individuals affected with SMPD1-related conditions. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.18
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
11
DANN
Benign
0.80
Eigen
Benign
-0.82
Eigen_PC
Benign
-0.77
FATHMM_MKL
Benign
0.064
N
LIST_S2
Benign
0.58
T;T
M_CAP
Benign
0.049
D
MetaRNN
Benign
0.082
T;T
MetaSVM
Benign
-0.68
T
PhyloP100
-0.39
PrimateAI
Benign
0.35
T
PROVEAN
Benign
-0.31
N;N
REVEL
Benign
0.16
Sift
Benign
0.89
T;T
Sift4G
Benign
0.90
T;T
Vest4
0.23
MVP
0.76
MPC
0.30
ClinPred
0.056
T
GERP RS
2.1
Varity_R
0.065
gMVP
0.60
Mutation Taster
=95/5
polymorphism

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

Other links and lift over

dbSNP: rs35785620; hg19: chr11-6415704; API