CASK

Chr XXLRX-linked

calcium/calmodulin dependent serine protein kinase

Also known as: CAGH39, CAMGUK, CMG, FGS4, LIN2, MICPCH, MRXSNA, TNRC8

The protein functions as a calcium/calmodulin-dependent serine protein kinase and MAGUK scaffold protein located at brain synapses. Mutations cause X-linked intellectual disability with variable features including FG syndrome 4, microcephaly with pontine and cerebellar hypoplasia, and nystagmus, predominantly through loss-of-function mechanisms. The gene shows extreme intolerance to loss-of-function variants, consistent with haploinsufficiency being pathogenic in hemizygous males.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
LOFmechanismXLR/X-linkedLOEUF 0.073 OMIM phenotypes
Clinical SummaryCASK
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Gene-Disease Validity (ClinGen)
X-linked syndromic intellectual disability · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
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Clinical Trials
1 active or recruiting trial — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Dual constrained — LoF & missense intolerant
LoF Constraint
0.07LOEUF
pLI 1.000
Z-score 5.93
OE 0.00 (0.000.07)
Highly constrained

Among the most LoF-intolerant genes (~top 3%)

Missense Constraint
4.25Z-score
OE missense 0.37 (0.320.43)
133 obs / 359.9 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.00 (0.000.07)
00.351.4
Missense OE0.37 (0.320.43)
00.61.4
Synonymous OE0.99
01.21.6
LoF obs/exp: 0 / 41.0Missense obs/exp: 133 / 359.9Syn Z: 0.08
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveCASK-related intellectual developmental disorder, with or without nystagmusOTHERXLR
definitiveCASK-related intellectual developmental disorderLOFmonoallelic_X_heterozygous
DN
0.3594th %ile
GOF
0.5563th %ile
LOF
0.73top 10%

The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).

LOFprediction above median · LOEUF 0.07

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CASK · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold
Clinical Literature
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