chr2-130152706-C-A

Variant names:

• chr2-130152706-C-A
• rs779013081
• NM_017951.5:c.2333G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_017951.5(SMPD4):​c.2333G>T​(p.Arg778Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000014 in 1,425,112 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R778Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SMPD4 NM_017951.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.14
• Publications: 0 publications found

Genes affected

SMPD4 (HGNC:32949): (sphingomyelin phosphodiesterase 4) The protein encoded by this gene is a sphingomyelinase that catalyzes the hydrolysis of membrane sphingomyelin to form phosphorylcholine and ceramide. This gene is activated by DNA damage, cellular stress, and tumor necrosis factor, but it is downregulated by wild-type p53. The encoded protein localizes to the endoplasmic reticulum and Golgi network. [provided by RefSeq, Mar 2017]

SMPD4 Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with microcephaly, arthrogryposis, and structural brain anomalies

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD4	NM_017951.5	c.2333G>T	p.Arg778Leu	missense_variant	Exon 20 of 20	ENST00000680298.1	NP_060421.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMPD4	ENST00000680298.1	c.2333G>T	p.Arg778Leu	missense_variant	Exon 20 of 20		NM_017951.5	ENSP00000506463.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000140 AC: 2 AN: 1425112 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 705762

African (AFR) AF: 0.00 AC: 0 AN: 32644

American (AMR) AF: 0.00 AC: 0 AN: 38644

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25446

East Asian (EAS) AF: 0.00 AC: 0 AN: 37652

South Asian (SAS) AF: 0.00 AC: 0 AN: 82060

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49978

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4822

European-Non Finnish (NFE) AF: 0.00000183 AC: 2 AN: 1094910

Other (OTH) AF: 0.00 AC: 0 AN: 58956

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Benign	23
DANN	Uncertain	1.0
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Uncertain	0.093	D
MetaRNN	Uncertain	0.61	D;D;D
MetaSVM	Uncertain	-0.099	T
PhyloP100		4.1
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-4.9	D;D;D
REVEL	Uncertain	0.53
Sift	Uncertain	0.0040	D;D;D
Sift4G	Uncertain	0.0040	D;D;D
Vest4		0.58
MVP		0.33
MPC		0.93
ClinPred		0.98	D
GERP RS		4.1
Varity_R		0.37
gMVP		0.71
Mutation Taster		=52/48	polymorphism

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

Other links and lift over

dbSNP: rs779013081; hg19: chr2-130910279;