X-53234946-TGATGGTGG-TGA

Variant names:

• chrX-53234947-GATGGTG-GA
• NM_001111125.3:c.3733_3737delCACCA

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001111125.3(IQSEC2):​c.3733_3737delCACCA​(p.His1245SerfsTer4) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. H1245H) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 21)
• Consequence: IQSEC2 NM_001111125.3 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.85
• 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), Ambry Genetics, G2P
• 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 10 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 34 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IQSEC2	NM_001111125.3	MANE Select	c.3733_3737delCACCA	p.His1245SerfsTer4	frameshift	Exon 15 of 15	NP_001104595.1	Q5JU85-2
	IQSEC2	NM_001410736.1		c.*218_*222delCACCA		3_prime_UTR	Exon 14 of 14	NP_001397665.1	A0A1W2PR28
	IQSEC2	NM_001441093.1		c.*218_*222delCACCA		3_prime_UTR	Exon 14 of 14	NP_001428022.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IQSEC2	ENST00000642864.1	MANE Select	c.3733_3737delCACCA	p.His1245SerfsTer4	frameshift	Exon 15 of 15	ENSP00000495726.1	Q5JU85-2
	IQSEC2	ENST00000375365.2	TSL:1	c.*218_*222delCACCA		3_prime_UTR	Exon 14 of 14	ENSP00000364514.2	Q5JU85-3
	IQSEC2	ENST00000706952.1		c.3892_3896delCACCA	p.His1298SerfsTer4	frameshift	Exon 15 of 15	ENSP00000516672.1	A0A9L9PY69

Frequencies

GnomAD3 genomes Cov.: 21

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 21

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.8

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chrX-53264129;