chr4-107895711-C-A

Position:

• chr4-107895711-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001375905.1(SGMS2):​c.158C>A​(p.Thr53Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T53T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SGMS2 NM_001375905.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.15

Genes affected

SGMS2 (HGNC:28395): (sphingomyelin synthase 2) Sphingomyelin, a major component of cell and Golgi membranes, is made by the transfer of phosphocholine from phosphatidylcholine onto ceramide, with diacylglycerol as a side product. The protein encoded by this gene is an enzyme that catalyzes this reaction primarily at the cell membrane. The synthesis is reversible, and this enzyme can catalyze the reaction in either direction. The encoded protein is required for cell growth. Three transcript variants encoding the same protein have been found for this gene. There is evidence for more variants, but the full-length nature of their transcripts has not been determined.[provided by RefSeq, Oct 2008]

CYP2U1-AS1 (HGNC:54817): (CYP2U1 and SGMS2 antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.075908184).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SGMS2	NM_001375905.1	c.158C>A	p.Thr53Asn	missense_variant	3/7	ENST00000690982.1
CYP2U1-AS1	NR_125929.1	n.150-2074G>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SGMS2	ENST00000690982.1	c.158C>A	p.Thr53Asn	missense_variant	3/7		NM_001375905.1	P1
CYP2U1-AS1	ENST00000656249.1	n.290-2074G>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 25, 2023

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant  is likely to be tolerated. This variant has not been reported in the literature in individuals affected with SGMS2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 53 of the SGMS2 protein (p.Thr53Asn). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.080
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.69
CADD	Benign	18
DANN	Benign	0.97
DEOGEN2	Benign	0.25	T;T;T
Eigen	Benign	-0.15
Eigen_PC	Benign	0.087
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.75	.;.;T
M_CAP	Benign	0.0047	T
MetaRNN	Benign	0.076	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.69	N;N;N
MutationTaster	Benign	0.79	N;N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-0.010	N;N;N
REVEL	Benign	0.050
Sift	Benign	0.30	T;T;T
Sift4G	Benign	0.28	T;T;T
Polyphen		0.0060	B;B;B
Vest4		0.085
MutPred		0.30		Loss of phosphorylation at T53 (P = 0.0165);Loss of phosphorylation at T53 (P = 0.0165);Loss of phosphorylation at T53 (P = 0.0165);
MVP		0.44
MPC		0.40
ClinPred		0.24	T
GERP RS		5.7
Varity_R		0.093
gMVP		0.32

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: rs754617588; hg19: chr4-108816867;