chrX-18604003-TC-T

Variant names:

• chrX-18604003-TC-T
• rs267608566
• NM_001323289.2:c.1082delC

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.1082delC​(p.Pro361LeufsTer7) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. P361P) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 22)
• Consequence: CDKL5 NM_001323289.2 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.119
• Publications: 0 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 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-18604003-TC-T is Pathogenic according to our data. Variant chrX-18604003-TC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2683760.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKL5	NM_001323289.2	c.1082delC	p.Pro361LeufsTer7	frameshift_variant	Exon 12 of 18	ENST00000623535.2	NP_001310218.1
CDKL5	NM_001037343.2	c.1082delC	p.Pro361LeufsTer7	frameshift_variant	Exon 13 of 22		NP_001032420.1
CDKL5	NM_003159.3	c.1082delC	p.Pro361LeufsTer7	frameshift_variant	Exon 12 of 21		NP_003150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKL5	ENST00000623535.2	c.1082delC	p.Pro361LeufsTer7	frameshift_variant	Exon 12 of 18	1	NM_001323289.2	ENSP00000485244.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 2 Pathogenic:1

Jan 05, 2024

Diagnostics Services (NGS), CSIR - Centre For Cellular And Molecular Biology

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1082del variant is not present in publicly available population databases like 1000 Genomes, EVS, ExAC, gnomAD, Indian Exome Database or our in-house exome database. This variant has neither been published in literature with TTC19-related conditions nor reported to clinical databases like ClinVar, Human Genome Mutation Database (HGMD) or OMIM, in any affected individuals. In-silico pathogenicity prediction programs like MutationTaster2, CADD, Varsome, Franklin etc predicted this variant to be likely deleterious. This variant causes frameshift at the 361st amino acid position of the wild-type transcript that creates a premature translational stop codon in the altered transcript that may either result in translation of a truncated protein or cause nonsense mediated decay of the mRNA. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.12

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: rs267608566; hg19: chrX-18622123;