Genetic Variant SMPDL3A:p.Ile250Thr (chr6-122804919-T-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_006714.5(SMPDL3A):c.749T>C(p.Ile250Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000559 in 1,611,190 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

SMPDL3A
NM_006714.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.67

Variant links:

Genes affected

SMPDL3A (HGNC:17389): (sphingomyelin phosphodiesterase acid like 3A) Enables phosphoric diester hydrolase activity and zinc ion binding activity. Involved in nucleoside triphosphate catabolic process. Located in extracellular space. [provided by Alliance of Genome Resources, Apr 2022]

SMPDL3A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.943

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPDL3A	NM_006714.5 link	c.749T>C	p.Ile250Thr	missense_variant	Exon 6 of 8	ENST00000368440.5	NP_006705.1	Q92484-1
SMPDL3A	NM_001286138.2 link	c.356T>C	p.Ile119Thr	missense_variant	Exon 5 of 7		NP_001273067.1	Q92484-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMPDL3A	ENST00000368440.5 link	c.749T>C	p.Ile250Thr	missense_variant	Exon 6 of 8	1	NM_006714.5	ENSP00000357425.4		Q92484-1
SMPDL3A	ENST00000539041.5 link	c.356T>C	p.Ile119Thr	missense_variant	Exon 5 of 7	2		ENSP00000442152.1		Q92484-2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152212

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:

0.000385

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:

0.00000803

AC:

AN:

249218

Hom.:

AF XY:

0.00000742

AC XY:

AN XY:

134778

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000411

AC:

AN:

1458978

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

725532

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000126

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152212

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000385

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 27, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.749T>C (p.I250T) alteration is located in exon 6 (coding exon 6) of the SMPDL3A gene. This alteration results from a T to C substitution at nucleotide position 749, causing the isoleucine (I) at amino acid position 250 to be replaced by a threonine (T). 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

0.33

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.31

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.48

.;T

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.78

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.88

D;D

M_CAP

Pathogenic

0.34

MetaRNN

Pathogenic

0.94

D;D

MetaSVM

Uncertain

0.70

MutationAssessor

Uncertain

2.9

.;M

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-4.1

D;D

REVEL

Pathogenic

0.90

Sift

Uncertain

0.020

D;D

Sift4G

Uncertain

0.0020

D;D

Polyphen

1.0

.;D

Vest4

0.94

MutPred

0.78

.;Loss of stability (P = 0.0376);

MVP

0.87

MPC

0.53

ClinPred

0.99

GERP RS

5.7

Varity_R

0.82

gMVP

0.93

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