X-25004887-AG-AGG

Variant names:

• chrX-25004887-A-AG
• rs797045292
• NM_139058.3:c.1471dupC

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_139058.3(ARX):​c.1471dupC​(p.Leu491ProfsTer41) variant causes a frameshift 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 Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. L491L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 25)
• Consequence: ARX NM_139058.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.71
• Publications: 4 publications found

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]

ARX Gene-Disease associations (from GenCC):

• genetic developmental and epileptic encephalopathy

  Inheritance: XL, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• intellectual disability, X-linked, with or without seizures, ARX-related

  Inheritance: XL Classification: DEFINITIVE, MODERATE Submitted by: Ambry Genetics, G2P
• Partington syndrome

  Inheritance: XL Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• X-linked complex neurodevelopmental disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• X-linked lissencephaly with abnormal genitalia

  Inheritance: XL Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• corpus callosum agenesis-abnormal genitalia syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• infantile epileptic-dyskinetic encephalopathy

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• non-syndromic X-linked intellectual disability

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• X-linked spasticity-intellectual disability-epilepsy syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 23 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-25004887-A-AG is Pathogenic according to our data. Variant chrX-25004887-A-AG is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 210321.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_139058.3. 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
	ARX	NM_139058.3	MANE Select	c.1471dupC	p.Leu491ProfsTer41	frameshift	Exon 5 of 5	NP_620689.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ARX	ENST00000379044.5	TSL:1 MANE Select	c.1471dupC	p.Leu491ProfsTer41	frameshift	Exon 5 of 5	ENSP00000368332.4
	ARX	ENST00000636885.1	TSL:5	n.59dupC		non_coding_transcript_exon	Exon 2 of 2

Frequencies

GnomAD3 genomes Cov.: 25

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 25

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	not provided (2)
1	-	-	X-linked lissencephaly with abnormal genitalia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.7
Mutation Taster		=3/197	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs797045292; hg19: chrX-25023004; COSMIC: COSV66874781; COSMIC: COSV66874781;