rs1556865060

Variant names:

• chrX-53255935-CA-C
• rs1556865060
• NM_001111125.3:c.863delT

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001111125.3(IQSEC2):​c.863delT​(p.Val288GlyfsTer18) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: IQSEC2 NM_001111125.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.05
• Publications: 0 publications found

Genes affected

IQSEC2 (HGNC:29059): (IQ motif and Sec7 domain ArfGEF 2) This gene encodes a guanine nucleotide exchange factor for the ARF family of small GTP-binding proteins. The encoded protein is a component of the postsynaptic density at excitatory synapses, and may play a critical role in cytoskeletal and synaptic organization through the activation of selected ARF substrates including ARF1 and ARF6. Mutations in this gene have been implicated in nonsyndromic X-linked cognitive disability. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Aug 2011]

IQSEC2 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: Ambry Genetics
• intellectual disability, X-linked 1

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• X-linked complex neurodevelopmental disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• non-syndromic X-linked intellectual disability

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• severe intellectual disability-progressive postnatal microcephaly- midline stereotypic hand movements syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-53255935-CA-C is Pathogenic according to our data. Variant chrX-53255935-CA-C is described in ClinVar as Pathogenic. ClinVar VariationId is 471277.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001111125.3. 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
	IQSEC2	NM_001111125.3	MANE Select	c.863delT	p.Val288GlyfsTer18	frameshift	Exon 3 of 15	NP_001104595.1
	IQSEC2	NM_001441092.1		c.863delT	p.Val288GlyfsTer18	frameshift	Exon 3 of 14	NP_001428021.1
	IQSEC2	NM_001410736.1		c.863delT	p.Val288GlyfsTer18	frameshift	Exon 3 of 14	NP_001397665.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IQSEC2	ENST00000642864.1	MANE Select	c.863delT	p.Val288GlyfsTer18	frameshift	Exon 3 of 15	ENSP00000495726.1
	IQSEC2	ENST00000375365.2	TSL:1	c.248delT	p.Val83GlyfsTer18	frameshift	Exon 3 of 14	ENSP00000364514.2
	IQSEC2	ENST00000638630.1	TSL:1	c.152delT	p.Val51GlyfsTer18	frameshift	Exon 2 of 4	ENSP00000492390.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 23

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Intellectual disability, X-linked 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.1
Mutation Taster		=0/200	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: rs1556865060; hg19: chrX-53285117;