X-25007238-AGGCGGCGGCGGC-AGGCGGCGGCGGCGGCGGCGGCGGC

Variant names:

• chrX-25007238-A-AGGCGGCGGCGGC
• rs398124508
• NM_139058.3:c.1309_1320dupGCCGCCGCCGCC

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP3

The NM_139058.3(ARX):​c.1309_1320dupGCCGCCGCCGCC​(p.Ala437_Ala440dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type INS_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A440A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 23)
• Consequence: ARX NM_139058.3 conservative_inframe_insertion
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.21
• Publications: 1 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: Likely_benign. The variant received -1 ACMG points.

• BP3: Nonframeshift variant in repetitive region in NM_139058.3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARX	NM_139058.3	c.1309_1320dupGCCGCCGCCGCC	p.Ala437_Ala440dup	conservative_inframe_insertion	Exon 4 of 5	ENST00000379044.5	NP_620689.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARX	ENST00000379044.5	c.1309_1320dupGCCGCCGCCGCC	p.Ala437_Ala440dup	conservative_inframe_insertion	Exon 4 of 5	1	NM_139058.3	ENSP00000368332.4
ARX	ENST00000637993.1	c.-81_-70dupGCCGCCGCCGCC		upstream_gene_variant		5		ENSP00000490122.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.2

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs398124508; hg19: chrX-25025355;