chr15-25370995-A-T

Variant names:

• chr15-25370995-A-T
• rs143000400
• NM_130839.5:c.1179T>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_130839.5(UBE3A):​c.1179T>A​(p.Asp393Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. D393D) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: UBE3A NM_130839.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.265
• Publications: 1 publications found

Genes affected

UBE3A (HGNC:12496): (ubiquitin protein ligase E3A) This gene encodes an E3 ubiquitin-protein ligase, part of the ubiquitin protein degradation system. This imprinted gene is maternally expressed in brain and biallelically expressed in other tissues. Maternally inherited deletion of this gene causes Angelman Syndrome, characterized by severe motor and intellectual retardation, ataxia, hypotonia, epilepsy, absence of speech, and characteristic facies. The protein also interacts with the E6 protein of human papillomavirus types 16 and 18, resulting in ubiquitination and proteolysis of tumor protein p53. Alternative splicing of this gene results in three transcript variants encoding three isoforms with different N-termini. Additional transcript variants have been described, but their full length nature has not been determined. [provided by RefSeq, Jul 2008]

SNHG14 (HGNC:37462): (small nucleolar RNA host gene 14) This gene is located within the Prader-Willi critical region and produces a long, spliced paternally-imprinted RNA that initiates within a common upstream promoter region shared by the SNRPN (small nuclear ribonucleoprotein polypeptide N) and SNURF genes. This transcript serves as a host RNA for the small nucleolar RNA, C/D box 115 and 116 clusters. This RNA extends in antisense into the region of the ubiquitin protein ligase E3A gene (UBE3A), and is thought to regulate imprinted expression of UBE3A in the brain. This transcript undergoes extensive alternative splicing, and may initiate and terminate at multiple locations within this genomic region. The full-length structure of all splice forms is not determined. [provided by RefSeq, Mar 2017]

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the UBE3A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 44 curated pathogenic missense variants (we use a threshold of 10). The gene has 8 curated benign missense variants. Trascript score misZ: 6.9443 (above the threshold of 3.09). GenCC associations: The gene is linked to Angelman syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.0637365).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_130839.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	UBE3A	NM_130839.5	MANE Select	c.1179T>A	p.Asp393Glu	missense	Exon 6 of 13	NP_570854.1
	UBE3A	NM_000462.5		c.1188T>A	p.Asp396Glu	missense	Exon 7 of 14	NP_000453.2
	UBE3A	NM_001354505.1		c.1179T>A	p.Asp393Glu	missense	Exon 6 of 13	NP_001341434.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	UBE3A	ENST00000648336.2	MANE Select	c.1179T>A	p.Asp393Glu	missense	Exon 6 of 13	ENSP00000497572.2
	UBE3A	ENST00000566215.5	TSL:1	c.1119T>A	p.Asp373Glu	missense	Exon 8 of 15	ENSP00000457771.1
	SNHG14	ENST00000424333.6	TSL:1	n.5767-47793A>T		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461856 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727222

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

May 09, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Angelman syndrome Uncertain:1

Apr 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt UBE3A protein function. ClinVar contains an entry for this variant (Variation ID: 423562). This variant has not been reported in the literature in individuals affected with UBE3A-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 373 of the UBE3A protein (p.Asp373Glu).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.063
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	7.2
DANN	Benign	0.87
DEOGEN2	Benign	0.099	T
Eigen	Benign	-0.93
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.19	N
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.0065	T
MetaRNN	Benign	0.064	T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	0.34	N
PhyloP100		-0.27
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-0.050	N
REVEL	Benign	0.21
Sift	Benign	0.52	T
Sift4G	Benign	1.0	T
Polyphen		0.0	B
Vest4		0.11
MutPred		0.31		Gain of solvent accessibility (P = 0.0854)
MVP		0.44
MPC		0.86
ClinPred		0.30	T
GERP RS		0.12
Varity_R		0.023
gMVP		0.13

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

Other links and lift over

dbSNP: rs143000400; hg19: chr15-25616142;