X-25013486-C-T

Position:

• chrX-25013486-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_139058.3(ARX):​c.509G>A​(p.Ser170Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: ARX NM_139058.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.18

Genes affected

ARX (HGNC:18060): (aristaless related homeobox) This gene is a homeobox-containing gene expressed during development. The expressed protein contains two conserved domains, a C-peptide (or aristaless domain) and the prd-like class homeobox domain. It is a member of the group-II aristaless-related protein family whose members are expressed primarily in the central and/or peripheral nervous system. This gene is thought to be involved in CNS development. Expansion of a polyalanine tract and other mutations in this gene cause X-linked cognitive disability and epilepsy. [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARX	NM_139058.3	c.509G>A	p.Ser170Asn	missense_variant	2/5	ENST00000379044.5	NP_620689.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARX	ENST00000379044.5	c.509G>A	p.Ser170Asn	missense_variant	2/5	1	NM_139058.3	ENSP00000368332.4

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 795904 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 245542

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual disability, X-linked, with or without seizures, arx-related;C3463992:Developmental and epileptic encephalopathy, 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 20, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C45"). This variant has not been reported in the literature in individuals with ARX-related disease. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This sequence change replaces serine with asparagine at codon 170 of the ARX protein (p.Ser170Asn). The serine residue is highly conserved and there is a small physicochemical difference between serine and asparagine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Benign	0.0061	T
BayesDel_noAF	Benign	-0.23
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.29	T
FATHMM_MKL	Benign	0.53	D
LIST_S2	Benign	0.55	T
M_CAP	Pathogenic	0.95	D
MetaRNN	Uncertain	0.44	T
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Benign	1.9	L
PrimateAI	Pathogenic	0.95	D
PROVEAN	Benign	-1.1	N
REVEL	Uncertain	0.47
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.015	D
Polyphen		0.99	D
Vest4		0.27
MutPred		0.25		Gain of relative solvent accessibility (P = 0.0215);
MVP		0.94
MPC		1.1
ClinPred		0.87	D
GERP RS		2.7
Varity_R		0.75
gMVP		0.61

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1556056051; hg19: chrX-25031603;