rs1556863492

chrX-53251017-AGGTAGAGG-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001111125.3(IQSEC2):c.1551_1558del(p.Leu518GlyfsTer2) variant causes a frameshift change involving the alteration of a conserved nucleotide. 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: 7.50

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]

ACMG classification

Verdict is Pathogenic. Variant got 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-53251017-AGGTAGAGG-A is Pathogenic according to our data. Variant chrX-53251017-AGGTAGAGG-A is described in ClinVar as [Pathogenic]. Clinvar id is 538603.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IQSEC2	NM_001111125.3	c.1551_1558del	p.Leu518GlyfsTer2	frameshift_variant	5/15	ENST00000642864.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IQSEC2	ENST00000642864.1	c.1551_1558del	p.Leu518GlyfsTer2	frameshift_variant	5/15		NM_001111125.3	P1

Frequencies

GnomAD3 genomes Cov.: 23

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

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual disability, X-linked 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 02, 2017

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in IQSEC2 are known to be pathogenic (PMID: 21686261, 26793055, 27665735). This variant has not been reported in the literature in individuals with IQSEC2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Leu518Glyfs*2) in the IQSEC2 gene. It is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1556863492; hg19: chrX-53280199;