X-41520444-C-T

Variant names:

• chrX-41520444-C-T
• rs1555971887
• NM_001367721.1:c.2757G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001367721.1(CASK):​c.2757G>A​(p.Trp919*) variant causes a stop gained 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. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: CASK NM_001367721.1 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.57

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-AS1 (HGNC:40126): (CASK antisense RNA 1)

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 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. Fraction of 0.00863 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-41520444-C-T is Pathogenic according to our data. Variant chrX-41520444-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 523767.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CASK	NM_001367721.1	c.2757G>A	p.Trp919*	stop_gained	Exon 27 of 27	ENST00000378163.7	NP_001354650.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CASK	ENST00000378163.7	c.2757G>A	p.Trp919*	stop_gained	Exon 27 of 27	5	NM_001367721.1	ENSP00000367405.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Mar 07, 2018

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The W914X variant in the CASK gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is predicted to cause loss of normal protein function through protein truncation. The W914X variant is not observed in large population cohorts (Lek et al., 2016). We interpret W914X as a pathogenic variant, consistent with the bilateral optic atrophy and global developmental delay reported in this individual. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	37
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.65
GERP RS		5.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555971887; hg19: chrX-41379697;