Genetic Variant SMPD2:p.Ser75Ser (chr6-109441974-C-T) – ACMG Classification: Likely_benign (-5 pts)

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 2P and 7B. PM2BP4_StrongBP6_ModerateBP7

The NM_003080.3(SMPD2):c.225C>T(p.Ser75Ser) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,613,668 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

Frequency

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

Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

SMPD2
NM_003080.3 splice_region, synonymous

Scores

Splicing: ADA: 0.0004991

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -1.95

Variant links:

Genes affected

SMPD2 (HGNC:11121): (sphingomyelin phosphodiesterase 2) This gene encodes a protein which was initially identified as a sphingomyelinase based on sequence similarity between bacterial sphingomyelinases and a yeast protein. Subsequent studies showed that its biological function is less likely to be as a sphingomyelinase and instead as a lysophospholipase. [provided by RefSeq, Oct 2009]

SMPD2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.51).

BP6

Variant 6-109441974-C-T is Benign according to our data. Variant chr6-109441974-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 3799238.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

Synonymous conserved (PhyloP=-1.95 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD2	NM_003080.3 link	c.225C>T	p.Ser75Ser	splice_region_variant, synonymous_variant	Exon 4 of 10	ENST00000258052.8	NP_003071.2	O60906
SMPD2	XM_011536079.2 link	c.-91C>T		5_prime_UTR_variant	Exon 2 of 8		XP_011534381.1
SMPD2	XR_942566.3 link	n.623C>T		splice_region_variant, non_coding_transcript_exon_variant	Exon 4 of 10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMPD2	ENST00000258052.8 link	c.225C>T	p.Ser75Ser	splice_region_variant, synonymous_variant	Exon 4 of 10	1	NM_003080.3	ENSP00000258052.3		O60906
SMPD2	ENST00000439615.1 link	n.27C>T		splice_region_variant, non_coding_transcript_exon_variant	Exon 2 of 3	3

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152198

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

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251468

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135902

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000178

AC:

AN:

1461470

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727074

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000189

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74348

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.00000756

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Benign:1

Mar 08, 2025

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.51

CADD

Benign

9.3

DANN

Benign

0.71

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00050

dbscSNV1_RF

Benign

0.082

SpliceAI score (max)

0.070

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