NM_001323289.2:c.-162-2A>G

Variant names:

• chrX-18506933-A-G
• rs786204973
• NM_001323289.2:c.-162-2A>G

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.-162-2A>G variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: CDKL5 NM_001323289.2 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 4.78
• 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 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.3, offset of -26, new splice context is: tgcaaatataaaacttacAGctt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-18506933-A-G is Pathogenic according to our data. Variant chrX-18506933-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 189565.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.-162-2A>G		splice_acceptor_variant, intron_variant	Intron 1 of 17	ENST00000623535.2	NP_001310218.1
CDKL5	NM_001037343.2	c.-162-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 21		NP_001032420.1
CDKL5	NM_003159.3	c.-162-2A>G		splice_acceptor_variant, intron_variant	Intron 1 of 20		NP_003150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKL5	ENST00000623535.2	c.-162-2A>G		splice_acceptor_variant, intron_variant	Intron 1 of 17	1	NM_001323289.2	ENSP00000485244.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 328559 Hom.: 0 Cov.: 3 AF XY: 0.00 AC XY: 0 AN XY: 105131

African (AFR) AF: 0.00 AC: 0 AN: 9697

American (AMR) AF: 0.00 AC: 0 AN: 14663

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 10621

East Asian (EAS) AF: 0.00 AC: 0 AN: 22831

South Asian (SAS) AF: 0.00 AC: 0 AN: 24886

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 26134

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 2621

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 197538

Other (OTH) AF: 0.00 AC: 0 AN: 19568

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

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

Splice site mutation causing skipping of exon 2 (loss of AUG codon) -

CDKL5 disorder Pathogenic:1

Sep 20, 2024

Centre for Population Genomics, CPG

Significance: Likely 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 likely pathogenic. At least the following criteria are met: This variant has been identified as a de novo occurrence in an individual with CDKL5 disorder without confirmation of paternity and maternity (PM6, PMID: 19793311). Well-established in vitro or in vivo functional studies strongly supportive of a damaging effect on the protein function (PS3). This variant is absent from gnomAD (PM2_Supporting). -

not provided Pathogenic:1

Nov 08, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Observed in hemizygous state in a patient with seizures in the literature (Dimassi et al., 2015); Canonical splice site variant predicted to result in a null allele in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts; however, limited data are available (Lek et al., 2016); This variant is associated with the following publications: (PMID: 29264392, 25525159, 22670135, 22779007, 27054081, 19793311) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Uncertain	-0.050
CADD	Benign	22
DANN	Uncertain	0.98
PhyloP100		4.8
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.84

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

Other links and lift over

dbSNP: rs786204973; hg19: chrX-18525053;