6-122804937-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_006714.5(SMPDL3A):c.767G>T(p.Gly256Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,478 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: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: SMPDL3A NM_006714.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.60

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]

ACMG classification

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, 0.976

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMPDL3A	NM_006714.5	c.767G>T	p.Gly256Val	missense_variant	6/8	ENST00000368440.5
SMPDL3A	NM_001286138.2	c.374G>T	p.Gly125Val	missense_variant	5/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMPDL3A	ENST00000368440.5	c.767G>T	p.Gly256Val	missense_variant	6/8	1	NM_006714.5	P1
SMPDL3A	ENST00000539041.5	c.374G>T	p.Gly125Val	missense_variant	5/7	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459478 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 725866

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

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 Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 14, 2023

The c.767G>T (p.G256V) alteration is located in exon 6 (coding exon 6) of the SMPDL3A gene. This alteration results from a G to T substitution at nucleotide position 767, causing the glycine (G) at amino acid position 256 to be replaced by a valine (V). 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	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.47
Cadd	Uncertain	25
Dann	Uncertain	1.0
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	0.97	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-8.4	D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.99
MutPred		0.82		.;Loss of disorder (P = 0.1218);
MVP		0.96
MPC		0.53
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.99
gMVP		0.96

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

Other links and lift over

dbSNP: rs750958163; hg19: chr6-123126082;