NM_139058.3:c.921C>T

Variant names:

• chrX-25013074-G-A
• rs398124519
• NM_139058.3:c.921C>T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_139058.3(ARX):​c.921C>T​(p.Gly307Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000276 in 1,087,319 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. G307G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 24)
  • Exomes 𝑓: 0.0000028 (0 hom. 1 hem.)
• Consequence: ARX NM_139058.3 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 1.01
• Publications: 0 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 -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.5).
• BP6: Variant X-25013074-G-A is Benign according to our data. Variant chrX-25013074-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 1481930.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=1.01 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARX	NM_139058.3	c.921C>T	p.Gly307Gly	synonymous_variant	Exon 2 of 5	ENST00000379044.5	NP_620689.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARX	ENST00000379044.5	c.921C>T	p.Gly307Gly	synonymous_variant	Exon 2 of 5	1	NM_139058.3	ENSP00000368332.4

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD2 exomes AF: 0.00000629 AC: 1 AN: 158968 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000147

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000276 AC: 3 AN: 1087319 Hom.: 0 Cov.: 32 AF XY: 0.00000281 AC XY: 1 AN XY: 355409

African (AFR) AF: 0.00 AC: 0 AN: 26277

American (AMR) AF: 0.00 AC: 0 AN: 34257

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19144

East Asian (EAS) AF: 0.00 AC: 0 AN: 29882

South Asian (SAS) AF: 0.00 AC: 0 AN: 52446

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 39216

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3295

European-Non Finnish (NFE) AF: 0.00000358 AC: 3 AN: 837193

Other (OTH) AF: 0.00 AC: 0 AN: 45609

GnomAD4 genome Cov.: 24

ClinVar

Significance: Likely benign

Submissions summary: Benign: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 Benign:1

Dec 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.50
CADD	Benign	12
DANN	Benign	0.87
PhyloP100		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs398124519; hg19: chrX-25031191;