Genetic Variant SMPD1:p.Arg17Trp (chr11-6390647-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_000543.5(SMPD1):c.49C>T(p.Arg17Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,058 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R17Q) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SMPD1
NM_000543.5 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -1.61

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.05766958).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD1	NM_000543.5 link	c.49C>T	p.Arg17Trp	missense_variant	Exon 1 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.49C>T	p.Arg17Trp	missense_variant	Exon 1 of 6	1	NM_000543.5	ENSP00000340409.4		P17405-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152106

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1460952

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726826

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33462

American (AMR)

AF:

0.00

AC:

AN:

44678

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26102

East Asian (EAS)

AF:

0.00

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86224

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52926

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111778

Other (OTH)

AF:

0.00

AC:

AN:

60332

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152106

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74302

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41416

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5160

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68014

Other (OTH)

AF:

0.00

AC:

AN:

2094

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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.084

BayesDel_addAF

Benign

-0.31

BayesDel_noAF

Benign

-0.68

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.29

T;.

Eigen

Benign

-1.2

Eigen_PC

Benign

-1.3

FATHMM_MKL

Benign

0.033

LIST_S2

Benign

0.76

T;T

M_CAP

Benign

0.0061

MetaRNN

Benign

0.058

T;T

MetaSVM

Benign

-0.98

MutationAssessor

Benign

-0.34

N;N

PhyloP100

-1.6

PrimateAI

Benign

0.28

PROVEAN

Benign

-0.080

N;N

REVEL

Benign

0.023

Sift

Benign

0.060

T;T

Sift4G

Benign

0.066

T;T

Vest4

0.097

MutPred

0.39

Loss of disorder (P = 0.0542);Loss of disorder (P = 0.0542);

MVP

0.26

MPC

0.22

ClinPred

0.13

GERP RS

-4.9

PromoterAI

-0.068

Neutral

(source)

Varity_R

0.054

gMVP

0.49

Mutation Taster

=88/12

polymorphism

(source)

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

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11-6390647-C-T

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over