X-119835013-C-T

Variant names:

• chrX-119835013-C-T
• NM_080632.3:c.1317G>A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_080632.3(UPF3B):​c.1317G>A​(p.Met439Ile) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: UPF3B NM_080632.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.58

Genes affected

UPF3B (HGNC:20439): (UPF3B regulator of nonsense mediated mRNA decay) This gene encodes a protein that is part of a post-splicing multiprotein complex involved in both mRNA nuclear export and mRNA surveillance. The encoded protein is one of two functional homologs to yeast Upf3p. mRNA surveillance detects exported mRNAs with truncated open reading frames and initiates nonsense-mediated mRNA decay (NMD). When translation ends upstream from the last exon-exon junction, this triggers NMD to degrade mRNAs containing premature stop codons. This protein binds to the mRNA and remains bound after nuclear export, acting as a nucleocytoplasmic shuttling protein. It forms with Y14 a complex that binds specifically 20 nt upstream of exon-exon junctions. This gene is located on the long arm of chromosome X. Two splice variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.36534175).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
UPF3B	NM_080632.3	c.1317G>A	p.Met439Ile	missense_variant	Exon 11 of 11	ENST00000276201.7	NP_542199.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
UPF3B	ENST00000276201.7	c.1317G>A	p.Met439Ile	missense_variant	Exon 11 of 11	1	NM_080632.3	ENSP00000276201.3
UPF3B	ENST00000345865.6	c.1278G>A	p.Met426Ile	missense_variant	Exon 10 of 10	1		ENSP00000245418.2

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Syndromic X-linked intellectual disability 14 Uncertain:1

Jan 01, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 439 of the UPF3B protein (p.Met439Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with UPF3B-related conditions. Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt UPF3B protein function with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Benign	19
DANN	Benign	0.88
DEOGEN2	Benign	0.037	T;.
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Benign	0.079	D
MetaRNN	Benign	0.37	T;T
MetaSVM	Uncertain	-0.16	T
MutationAssessor	Benign	0.36	N;.
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-1.3	N;N
REVEL	Uncertain	0.39
Sift	Benign	0.66	T;T
Sift4G	Benign	0.57	T;T
Polyphen		0.85	P;P
Vest4		0.37
MutPred		0.26		Gain of sheet (P = 0.0125);.;
MVP		0.86
MPC		0.82
ClinPred		0.88	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.73
gMVP		0.034

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

No publications associated with this variant yet.

Other links and lift over

hg19: chrX-118968976;