rs267608643

Variant names:

• chrX-18604572-C-T
• rs267608643
• NM_001323289.2:c.1648C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001323289.2(CDKL5):​c.1648C>T​(p.Arg550*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 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 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 2.73
• Publications: 12 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 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-18604572-C-T is Pathogenic according to our data. Variant chrX-18604572-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 143780.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKL5	NM_001323289.2	c.1648C>T	p.Arg550*	stop_gained	Exon 12 of 18	ENST00000623535.2	NP_001310218.1
CDKL5	NM_001037343.2	c.1648C>T	p.Arg550*	stop_gained	Exon 13 of 22		NP_001032420.1
CDKL5	NM_003159.3	c.1648C>T	p.Arg550*	stop_gained	Exon 12 of 21		NP_003150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKL5	ENST00000623535.2	c.1648C>T	p.Arg550*	stop_gained	Exon 12 of 18	1	NM_001323289.2	ENSP00000485244.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Developmental and epileptic encephalopathy, 2 Pathogenic:5

Sep 02, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with developmental and epileptic encephalopathy 2 (MIM#300672). (I) 0110 - This gene is associated with X-linked dominant disease. (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0701 - Other NMD-predicted variants comparable to the one identified in this case have very strong previous evidence for pathogenicity (DECIPHER). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been classified as pathogenic by clinical laboratories in ClinVar and identified in individuals with epileptic encephalopathy and early-onset seizures in the literature (PMID: PMID:22678952, PMID:18063413, PMID:33436160, PMID:27599155). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Mar 13, 2014

RettBASE

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

- -

Feb 26, 2024

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been previously reported as de novo in a similarly affected individual (PMID: 19241098). The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000143780 /PMID: 18063413 /3billion dataset). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Jul 30, 2021

Undiagnosed Diseases Network, NIH

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Centre de Biologie Pathologie Génétique, Centre Hospitalier Universitaire de Lille

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:2

Oct 01, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in association with atypical Rett syndrome and CDKL5-related disorders (Pintaudi et al., 2008; Rademacher et al., 2011; Bahi-Buisson et al., 2012); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 29264392, 27599155, 25525159, 19241098, 18063413, 21318334, 29655203, 31313283, 31232219, 33714067, 33436160, 33047306, 35153983, 22678952) -

Nov 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

CDKL5 disorder Pathogenic:1

Aug 21, 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). Has been observed in at least 2 individuals with phenotypes consistent with CDKL5 disorder (PS4_Supporting). PMID18063413 ClinVar Variation ID: 143780 This variant is absent from gnomAD v4 (PM2_Supporting). -

Atypical Rett syndrome Pathogenic:1

Mar 13, 2014

RettBASE

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

- -

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

Jun 27, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This premature translational stop signal has been observed in individuals with clinical features of CDKL5-related conditions (PMID: 18063413, 21318334, 22678952). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg550*) 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). ClinVar contains an entry for this variant (Variation ID: 143780). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	35
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		2.7
Vest4		0.96
GERP RS		3.1
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs267608643; hg19: chrX-18622692; COSMIC: COSV66111274; COSMIC: COSV66111274;