chrX-18628376-GC-G

Variant names:

• chrX-18628376-GC-G
• rs267608660
• NM_001323289.2:c.2504delC

Variant summary

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

The NM_001323289.2(CDKL5):​c.2504delC​(p.Pro835HisfsTer2) 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 (★). Synonymous variant affecting the same amino acid position (i.e. P835P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 22)
• Consequence: CDKL5 NM_001323289.2 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.56
• Publications: 2 publications found

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]

CDKL5 Gene-Disease associations (from GenCC):

• CDKL5 disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 2

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• atypical Rett syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• precocious puberty

  Inheritance: XL Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 12 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 37 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-18628376-GC-G is Pathogenic according to our data. Variant chrX-18628376-GC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 143805.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001323289.2. 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
	CDKL5	NM_001323289.2	MANE Select	c.2504delC	p.Pro835HisfsTer2	frameshift	Exon 18 of 18	NP_001310218.1
	CDKL5	NM_001037343.2		c.2504delC	p.Pro835HisfsTer2	frameshift	Exon 19 of 22	NP_001032420.1
	CDKL5	NM_003159.3		c.2504delC	p.Pro835HisfsTer2	frameshift	Exon 18 of 21	NP_003150.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CDKL5	ENST00000623535.2	TSL:1 MANE Select	c.2504delC	p.Pro835HisfsTer2	frameshift	Exon 18 of 18	ENSP00000485244.1
	CDKL5	ENST00000379989.6	TSL:1	c.2504delC	p.Pro835HisfsTer2	frameshift	Exon 19 of 22	ENSP00000369325.3
	CDKL5	ENST00000379996.7	TSL:1	c.2504delC	p.Pro835HisfsTer2	frameshift	Exon 18 of 21	ENSP00000369332.3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 2 Pathogenic:1

Mar 13, 2014

RettBASE

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

CDKL5 disorder Pathogenic:1

Aug 23, 2024

Centre for Population Genomics, CPG

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

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:20397747 PMID:25657822 PMID:22670135

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.6
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs267608660; hg19: chrX-18646496;