Okur-Chung Neurodevelopmental Syndrome Curation Notes

Date: 2026-04-09

Disease Anchoring

Primary disease term used in the YAML entry: MONDO:0014893 Okur-Chung neurodevelopmental syndrome
Cross-references found locally in repo source tables:
OMIM:617062
Orphanet:689422
Naming decision:
Entry title kept as Okur-Chung Neurodevelopmental Syndrome
Synonyms include OCNDS, Okur-Chung syndrome, and CSNK2A1-related neurodevelopmental disorder

Existing repo triage rows classify the gene-disease mechanism as gain of function, but the primary literature is more mixed.
The YAML therefore treats OCNDS as a CSNK2A1-driven disorder with mechanistic heterogeneity:
reduced kinase activity for many missense variants
altered substrate specificity for at least some recurrent missense variants
probable haploinsufficiency for at least some null variants
This avoids overcommitting to a single gain-of-function model not supported across the disease spectrum.

PMID:27048600
Original disease-defining report
Established de novo CSNK2A1 variants and core features
PMID:29383814
11-individual clinical study
Supports hypotonia, swallowing difficulty, and congenital heart defects
PMID:29240241
8 additional cases
Supports high prevalence of neurodevelopmental delay and multisystem involvement
PMID:33944995
Functional variant study
Supports reduced CK2alpha kinase activity and abnormal localization
PMID:35517865
Mechanistic study of recurrent K198R
Supports altered substrate specificity rather than complete loss of function
PMID:39367055
Knock-in mouse model
Supports altered phosphoregulation, impaired synaptic maturation, and reduced hippocampal plasticity
PMID:39497417
Recent phenotype expansion
Supports microcephaly as common but under-recognized
PMID:40677894
Natural-history cohort
Supports conserved core phenotype, universal speech/language delay, and higher symptom burden in loop-region variants
PMID:38444259
Familial null-variant report
Supports haploinsufficiency as a potential mechanism and milder null-variant phenotypes
PMID:37491870
Familial transmission report
Supports autosomal dominant inherited OCNDS in addition to de novo disease
PMID:39070093
Patient-organization roadmap
Used only for rarity framing and the statement that there are no approved disease-modifying treatments

treatments
Omitted because current literature supports symptom management but not a validated disease-specific or disease-modifying intervention
biomarkers
Omitted because mutation location is still presented as a potential or exploratory stratifier rather than a clinically established biomarker
progression
Omitted because the available literature is stronger on core phenotype prevalence than on reproducible phase-based natural history staging