16-29664446-G-T

Variant names:

• chr16-29664446-G-T
• rs373992366
• NM_003123.6:c.718G>T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_003123.6(SPN):​c.718G>T​(p.Ala240Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,196 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: SPN NM_003123.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.67

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]

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.057258666).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPN	NM_003123.6	c.718G>T	p.Ala240Ser	missense_variant	Exon 2 of 2	ENST00000652691.1	NP_003114.1
SPN	NM_001030288.4	c.718G>T	p.Ala240Ser	missense_variant	Exon 2 of 2		NP_001025459.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPN	ENST00000652691.1	c.718G>T	p.Ala240Ser	missense_variant	Exon 2 of 2		NM_003123.6	ENSP00000498852.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152196 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251424 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135902

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152196 Hom.: 0 Cov.: 31 AF XY: 0.0000134 AC XY: 1 AN XY: 74352

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.085
BayesDel_addAF	Benign	-0.36	T
BayesDel_noAF	Benign	-0.76
CADD	Benign	0.0020
DANN	Benign	0.50
DEOGEN2	Benign	0.17	T;.;T
Eigen	Benign	-1.5
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.046	N
LIST_S2	Benign	0.28	.;T;T
M_CAP	Benign	0.0026	T
MetaRNN	Benign	0.057	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.69	N;.;N
PrimateAI	Benign	0.20	T
PROVEAN	Benign	-0.41	N;N;N
REVEL	Benign	0.043
Sift	Benign	0.097	T;T;T
Sift4G	Benign	0.50	T;T;T
Polyphen		0.062	B;.;B
Vest4		0.042
MVP		0.18
MPC		0.18
ClinPred		0.059	T
GERP RS		-7.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.086

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: rs373992366; hg19: chr16-29675767;