20-4182219-C-T

Variant summary

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

The NM_175839.3(SMOX):c.740C>T(p.Ala247Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000297 in 1,613,456 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000030 (0 hom.)
• Consequence: SMOX NM_175839.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.94

Genes affected

SMOX (HGNC:15862): (spermine oxidase) Polyamines are ubiquitous polycationic alkylamines which include spermine, spermidine, putrescine, and agmatine. These molecules participate in a broad range of cellular functions which include cell cycle modulation, scavenging reactive oxygen species, and the control of gene expression. These molecules also play important roles in neurotransmission through their regulation of cell-surface receptor activity, involvement in intracellular signalling pathways, and their putative roles as neurotransmitters. This gene encodes an FAD-containing enzyme that catalyzes the oxidation of spermine to spermadine and secondarily produces hydrogen peroxide. Multiple transcript variants encoding different isoenzymes have been identified for this gene, some of which have failed to demonstrate significant oxidase activity on natural polyamine substrates. The characterized isoenzymes have distinctive biochemical characteristics and substrate specificities, suggesting the existence of additional levels of complexity in polyamine catabolism. [provided by RefSeq, Jul 2012]

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=0.21464509).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMOX	NM_175839.3	c.740C>T	p.Ala247Val	missense_variant	5/7	ENST00000305958.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMOX	ENST00000305958.9	c.740C>T	p.Ala247Val	missense_variant	5/7	1	NM_175839.3	P4

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152114 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000194

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0000941

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000400 AC: 10 AN: 250186 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135438

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000273

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000265

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000301 AC: 44 AN: 1461342 Hom.: 0 Cov.: 36 AF XY: 0.0000220 AC XY: 16 AN XY: 727014

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000403

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000216

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152114 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74296

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000194

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.0000941

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

ExAC AF: 0.0000330 AC: 4

Asia WGS AF: 0.000289 AC: 1 AN: 3478

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 09, 2021

The c.740C>T (p.A247V) alteration is located in exon 5 (coding exon 4) of the SMOX gene. This alteration results from a C to T substitution at nucleotide position 740, causing the alanine (A) at amino acid position 247 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	0.20
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.38
Cadd	Benign	22
Dann	Uncertain	0.98
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.87	D;D;.;D;D;D
M_CAP	Benign	0.025	D
MetaRNN	Benign	0.21	T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.8	L;L;L;L;L;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.63	T
Sift4G	Benign	0.63	T;T;T;T;T;T
Polyphen		0.75	P;B;P;P;P;.
Vest4		0.71
MutPred		0.75		Loss of loop (P = 0.2237);Loss of loop (P = 0.2237);Loss of loop (P = 0.2237);Loss of loop (P = 0.2237);Loss of loop (P = 0.2237);.;
MVP		0.11
MPC		0.90
ClinPred		0.20	T
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.15
gMVP		0.71

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: rs767516409; hg19: chr20-4162866; COSMIC: COSV53864977; COSMIC: COSV53864977;