Genetic Variant CASK:c.2521-2A>G (chrX-41524036-T-C) – ACMG Classification: Pathogenic (12 pts)

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong

The NM_001367721.1(CASK):c.2521-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 22)

Exomes 𝑓: 0.0 ( 0 hom. 0 hem. )

Failed GnomAD Quality Control

Consequence

CASK
NM_001367721.1 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 7.33

Variant links:

Genes affected

CASK (HGNC:1497): (calcium/calmodulin dependent serine protein kinase) This gene encodes a calcium/calmodulin-dependent serine protein kinase. The encoded protein is a MAGUK (membrane-associated guanylate kinase) protein family member. These proteins are scaffold proteins and the encoded protein is located at synapses in the brain. Mutations in this gene are associated with FG syndrome 4, intellectual disability and microcephaly with pontine and cerebellar hypoplasia, and a form of X-linked intellectual disability. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2017]

CASK links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.030204963 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.5, offset of -30, new splice context is: tagttatttcttcttttaAGtcg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant X-41524036-T-C is Pathogenic according to our data. Variant chrX-41524036-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 265316.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
CASK	NM_001367721.1 link	c.2521-2A>G		splice_acceptor_variant, intron_variant	Intron 25 of 26	ENST00000378163.7	NP_001354650.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CASK	ENST00000378163.7 link	c.2521-2A>G		splice_acceptor_variant, intron_variant	Intron 25 of 26	5	NM_001367721.1	ENSP00000367405.1		O14936-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Data not reliable, filtered out with message: AC0;AS_VQSR

AF:

0.00

AC:

AN:

1030453

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

308049

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Dystonic disorder;C0028738:Nystagmus;C0560046:Inability to walk

Pathogenic:1

Jan 01, 2017

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

FG syndrome 4

Pathogenic:1

May 01, 2010

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided

Pathogenic:1

Mar 26, 2015

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2506-2 A>G splice site variant in the CASK gene destroys the canonical splice acceptor site in intron 25. It is predicted to cause abnormal gene splicing, either leading to an abnormal message that is subject to nonsense-mediated mRNA decay, or to an abnormal protein product if the message is used for protein translation. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.74

BayesDel_noAF

Uncertain

-0.020

CADD

Pathogenic

DANN

Uncertain

0.98

FATHMM_MKL

Pathogenic

0.99

GERP RS

5.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.87

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.55

Position offset: -11

DS_AL_spliceai

1.0

Position offset: -2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over