Genetic Variant SPN:p.Leu158Leu (chr16-29664202-G-A) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2BP4_StrongBP6BP7

The NM_003123.6(SPN):c.474G>A(p.Leu158Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000101 in 1,613,586 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 Likely benign (no stars).

Frequency

Genomes: 𝑓 0.000086 ( 0 hom., cov: 31)

Exomes 𝑓: 0.00010 ( 0 hom. )

Consequence

SPN
NM_003123.6 synonymous

Scores

Clinical Significance

Likely benign no assertion criteria provided B:1

Conservation

PhyloP100: 1.07

Variant links:

Genes affected

SPN (HGNC:11249): (sialophorin) This gene encodes a highly sialylated glycoprotein that functions in antigen-specific activation of T cells, and is found on the surface of thymocytes, T lymphocytes, monocytes, granulocytes, and some B lymphocytes. It contains a mucin-like extracellular domain, a transmembrane region and a carboxy-terminal intracellular region. The extracellular domain has a high proportion of serine and threonine residues, allowing extensive O-glycosylation, and has one potential N-glycosylation site, while the carboxy-terminal region has potential phosphorylation sites that may mediate transduction of activation signals. Different glycoforms of this protein have been described. In stimulated immune cells, proteolytic cleavage of the extracellular domain occurs in some cell types, releasing a soluble extracellular fragment. Defects in expression of this gene are associated with Wiskott-Aldrich syndrome. [provided by RefSeq, Sep 2017]

SPN links:

QPRT (HGNC:9755): (quinolinate phosphoribosyltransferase) This gene encodes a key enzyme in catabolism of quinolinate, an intermediate in the tryptophan-nicotinamide adenine dinucleotide pathway. Quinolinate acts as a most potent endogenous exitotoxin to neurons. Elevation of quinolinate levels in the brain has been linked to the pathogenesis of neurodegenerative disorders such as epilepsy, Alzheimer's disease, and Huntington's disease. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2015]

QPRT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.8).

BP6

Variant 16-29664202-G-A is Benign according to our data. Variant chr16-29664202-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 3047529.Status of the report is no_assertion_criteria_provided, 0 stars.

BP7

Synonymous conserved (PhyloP=1.07 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPN	NM_003123.6 link	c.474G>A	p.Leu158Leu	synonymous_variant	Exon 2 of 2	ENST00000652691.1	NP_003114.1	P16150A0A024R629
SPN	NM_001030288.4 link	c.474G>A	p.Leu158Leu	synonymous_variant	Exon 2 of 2		NP_001025459.1	P16150A0A024R629

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPN	ENST00000652691.1 link	c.474G>A	p.Leu158Leu	synonymous_variant	Exon 2 of 2		NM_003123.6	ENSP00000498852.1		P16150

Frequencies

GnomAD3 genomes

AF:

0.0000857

AC:

AN:

151702

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000658

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000162

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000796

AC:

AN:

251400

Hom.:

AF XY:

0.0000736

AC XY:

AN XY:

135878

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000132

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000103

AC:

150

AN:

1461884

Hom.:

Cov.:

AF XY:

0.000103

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000157

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000125

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000857

AC:

AN:

151702

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74052

show subpopulations

Gnomad4 AFR

AF:

0.0000242

Gnomad4 AMR

AF:

0.0000658

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000162

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000147

Hom.:

Bravo

AF:

0.000132

EpiCase

AF:

0.000327

EpiControl

AF:

0.000178

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

SPN-related disorder

Benign:1

Mar 22, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.80

CADD

Benign

2.7

DANN

Benign

0.69

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over