rs34176522

chr3-31624950-C-Gchr3-31624950-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM4

The NM_178862.3(STT3B):c.1764C>G(p.Tyr588Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. Y588Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: STT3B NM_178862.3 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.49

Genes affected

STT3B (HGNC:30611): (STT3 oligosaccharyltransferase complex catalytic subunit B) The protein encoded by this gene is a catalytic subunit of a protein complex that transfers oligosaccharides onto asparagine residues. Defects in this gene are a cause of congenital disorder of glycosylation Ix (CDG1X). [provided by RefSeq, Jun 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Stoplost variant in NM_178862.3 Downstream stopcodon found after 850 codons.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
STT3B	NM_178862.3	c.1764C>G	p.Tyr588Ter	stop_gained	12/16	ENST00000295770.4
STT3B	XM_017005858.2	c.1326C>G	p.Tyr442Ter	stop_gained	12/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
STT3B	ENST00000295770.4	c.1764C>G	p.Tyr588Ter	stop_gained	12/16	1	NM_178862.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250420 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135350

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: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	38
Dann	Uncertain	1.0
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Uncertain	0.96	D
MutationTaster	Benign	1.0	A
Vest4		0.50
GERP RS		4.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.41		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.41		Position offset: -36

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs34176522; hg19: chr3-31666442;