X-18575432-TGAAG-T

Position:

• chrX-18575432-TGAAG-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001323289.2(CDKL5):​c.229_232delGAAG​(p.Glu77fs) 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: CDKL5 NM_001323289.2 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.57

Genes affected

CDKL5 (HGNC:11411): (cyclin dependent kinase like 5) This gene is a member of Ser/Thr protein kinase family and encodes a phosphorylated protein with protein kinase activity. Mutations in this gene have been associated with X-linked infantile spasm syndrome (ISSX), also known as X-linked West syndrome, and Rett syndrome (RTT). Alternate transcriptional splice variants have been characterized. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 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-18575432-TGAAG-T is Pathogenic according to our data. Variant chrX-18575432-TGAAG-T is described in ClinVar as [Pathogenic]. Clinvar id is 143799.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-18575432-TGAAG-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDKL5	NM_001323289.2	c.229_232delGAAG	p.Glu77fs	frameshift_variant	5/18	ENST00000623535.2	NP_001310218.1
CDKL5	NM_001037343.2	c.229_232delGAAG	p.Glu77fs	frameshift_variant	6/22		NP_001032420.1
CDKL5	NM_003159.3	c.229_232delGAAG	p.Glu77fs	frameshift_variant	5/21		NP_003150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDKL5	ENST00000623535.2	c.229_232delGAAG	p.Glu77fs	frameshift_variant	5/18	1	NM_001323289.2	ENSP00000485244.1

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:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Developmental and epileptic encephalopathy, 2 Pathogenic:1

Pathogenic, no assertion criteria provided

curation

RettBASE

Mar 13, 2014

- -

CDKL5 disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

curation

Centre for Population Genomics, CPG

Sep 18, 2024

This variant has been collected from RettBASE and curated to current modified ACMG/AMP criteria. Based on the classification scheme defined by the ClinGen Rett/Angelman-like Expert Panel for Rett/AS-like Disorders Specifications to the ACMG/AMP Variant Interpretation Guidelines VCEP 3.0, this variant is classified as pathogenic. At least the following criteria are met: Predicted to result in loss of function, and LOF is a known mechanism of disease (PVS1). This variant is absent from gnomAD v4(PM2_Supporting). Has been observed in at least 2 individuals with phenotypes consistent with CDKL5 disorder (PS4_Supporting). PMID 18790821‚ 22872100, Variation ID: 143799 -

Developmental and epileptic encephalopathy, 2;CN128785:Angelman syndrome-like Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 24, 2021

For these reasons, this variant has been classified as Pathogenic. This variant has been observed in individual(s) with CDKL5-related conditions (PMID: 18790821). ClinVar contains an entry for this variant (Variation ID: 143799). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Glu77Hisfs*35) in the CDKL5 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CDKL5 are known to be pathogenic (PMID: 22872100). -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs267608441; hg19: chrX-18593552;