Genetic Variant SMPD3:p.Gly393Ser (chr16-68371005-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_018667.4(SMPD3):c.1177G>A(p.Gly393Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000774 in 1,614,140 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.00030 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000054 ( 0 hom. )

Consequence

SMPD3
NM_018667.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.51

Variant links:

Genes affected

SMPD3 (HGNC:14240): (sphingomyelin phosphodiesterase 3) Predicted to enable phosphatidic acid binding activity; phosphatidylserine binding activity; and sphingomyelin phosphodiesterase activity. Predicted to be involved in positive regulation of exosomal secretion and sphingomyelin metabolic process. Predicted to act upstream of or within several processes, including animal organ development; enzyme linked receptor protein signaling pathway; and sphingolipid metabolic process. Predicted to be located in Golgi apparatus and plasma membrane. Predicted to be active in cytoplasm. Biomarker of pulmonary emphysema. [provided by Alliance of Genome Resources, Apr 2022]

SMPD3 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.06777227).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD3	NM_018667.4 link	c.1177G>A	p.Gly393Ser	missense_variant	Exon 3 of 9	ENST00000219334.10	NP_061137.1	Q9NY59-1A8K0T6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMPD3	ENST00000219334.10 link	c.1177G>A	p.Gly393Ser	missense_variant	Exon 3 of 9	1	NM_018667.4	ENSP00000219334.5		Q9NY59-1

Frequencies

GnomAD3 genomes

AF:

0.000302

AC:

AN:

152206

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00106

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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

GnomAD3 exomes

AF:

0.0000956

AC:

AN:

251150

Hom.:

AF XY:

0.0000810

AC XY:

AN XY:

135820

show subpopulations

Gnomad AFR exome

AF:

0.000863

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000540

AC:

AN:

1461816

Hom.:

Cov.:

AF XY:

0.0000413

AC XY:

AN XY:

727212

show subpopulations

Gnomad4 AFR exome

AF:

0.00137

Gnomad4 AMR exome

AF:

0.000246

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.000302

AC:

AN:

152324

Hom.:

Cov.:

AF XY:

0.000268

AC XY:

AN XY:

74490

show subpopulations

Gnomad4 AFR

AF:

0.00106

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000894

Hom.:

Bravo

AF:

0.000400

ESP6500AA

AF:

0.00114

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Sep 04, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1177G>A (p.G393S) alteration is located in exon 3 (coding exon 1) of the SMPD3 gene. This alteration results from a G to A substitution at nucleotide position 1177, causing the glycine (G) at amino acid position 393 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.36

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Benign

0.36

T;T;.

Eigen

Benign

0.18

Eigen_PC

Uncertain

0.26

FATHMM_MKL

Uncertain

0.83

LIST_S2

Uncertain

0.89

D;D;D

M_CAP

Benign

0.019

MetaRNN

Benign

0.068

T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.0

L;.;L

PrimateAI

Benign

0.47

PROVEAN

Benign

-2.2

N;N;N

REVEL

Benign

0.13

Sift

Benign

0.30

T;T;T

Sift4G

Benign

0.49

T;T;T

Polyphen

0.96

P;.;.

Vest4

0.17

MVP

0.26

MPC

0.47

ClinPred

0.072

GERP RS

4.3

Varity_R

0.35

gMVP

0.65

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over