6-109442017-A-G

Position:

• chr6-109442017-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_003080.3(SMPD2):​c.268A>G​(p.Ile90Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SMPD2 NM_003080.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.03

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMPD2	NM_003080.3	c.268A>G	p.Ile90Val	missense_variant	4/10	ENST00000258052.8	NP_003071.2
SMPD2	XM_011536079.2	c.-48A>G		5_prime_UTR_variant	2/8		XP_011534381.1
SMPD2	XR_942566.3	n.666A>G		non_coding_transcript_exon_variant	4/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMPD2	ENST00000258052.8	c.268A>G	p.Ile90Val	missense_variant	4/10	1	NM_003080.3	ENSP00000258052.3
SMPD2	ENST00000439615.1	n.70A>G		non_coding_transcript_exon_variant	2/3	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461870 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727242

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000151

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

Feb 23, 2023

The c.268A>G (p.I90V) alteration is located in exon 4 (coding exon 4) of the SMPD2 gene. This alteration results from a A to G substitution at nucleotide position 268, causing the isoleucine (I) at amino acid position 90 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	Benign	0.12
BayesDel_addAF	Uncertain	0.017	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.35	T
Eigen	Pathogenic	0.73
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.61	T
M_CAP	Benign	0.013	T
MetaRNN	Uncertain	0.68	D
MetaSVM	Benign	-0.84	T
MutationAssessor	Uncertain	2.7	M
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.90	N
REVEL	Benign	0.25
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.99	D
Vest4		0.56
MVP		0.65
MPC		0.37
ClinPred		0.96	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.63
gMVP		0.69

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.31		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.31		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1423416282; hg19: chr6-109763220;