rs1556049714

Positions:

• chrX-25007424-G-A
• chrX-25007424-G-C
• chrX-25007424-G-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP3_Strong PP5_Moderate

The NM_139058.3(ARX):​c.1135C>T​(p.Arg379Cys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: ARX NM_139058.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.59

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 Pathogenic. Variant got 10 ACMG points.

• PM1: In a mutagenesis_site Abolishes sequence-specific DNA-binding; reduces transcriptional repression of LMO1 and SHOX2. Abolishes transcriptional activation of KDM5C. (size 0) in uniprot entity ARX_HUMAN
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant X-25007424-G-A is Pathogenic according to our data. Variant chrX-25007424-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 958198.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARX	NM_139058.3	c.1135C>T	p.Arg379Cys	missense_variant	4/5	ENST00000379044.5	NP_620689.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARX	ENST00000379044.5	c.1135C>T	p.Arg379Cys	missense_variant	4/5	1	NM_139058.3	ENSP00000368332.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1049589 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 340775

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.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic: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 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 17, 2023

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 379 of the ARX protein (p.Arg379Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with ARX-related conditions (PMID: 32613771; Invitae). ClinVar contains an entry for this variant (Variation ID: 958198). 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 expected to disrupt ARX protein function. This variant disrupts the p.Arg379 amino acid residue in ARX. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 20148114, 29152528). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.72	D
BayesDel_noAF	Pathogenic	0.79
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.3	H
PrimateAI	Pathogenic	0.95	D
PROVEAN	Pathogenic	-7.2	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.91
MutPred		0.95		Loss of disorder (P = 0.0266);
MVP		1.0
MPC		2.6
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.94
gMVP		0.99

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: rs1556049714; hg19: chrX-25025541;