Research Explained: Clinical Features of Okur-Chung Neurodevelopmental Syndrome: Case Report and Literature Review

Authors: Hossein Jafari Khamirani, Sina Zoghi, Ali Motealleh, Mehdi Dianatpour, Seyed Mohammad Bagher Tabei, Sanaz Mohammadi, Seyed Alireza Dastgheib

Publication Date: March 31, 2022

Research Explained By: Brad Davidson, CSNK2A1 Foundation Science Communication Intern

Link to article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9801326/

Research Explained Summary:

This case report presents an OCNDS patient who displayed regular seizures, an atypical characteristic for those with OCNDS. The patient presented to the clinic at age 8 due to cognitive, motor, and language developmental delays. At this time, the parents reported severe sleep issues and several episodeclinics of two different forms of seizures, known as myotonic and atonic. These seizures manifest differently: myotonic seizures are characterized by twitching and jerking of the arms and legs, whereas atonic seizures are characterized by a loss of muscle control and/or tension. Other OCNDS symptoms included behavioral issues, autism spectrum disorder, short stature, and muscle weakness (hypotonia). She also displayed poor dental development, although this had not yet been associated with OCNDS. 

Previously, the patient had been diagnosed with a urea cycle disorder, which causes toxic substances normally excreted through urination to build up in the bloodstream. As a result of this, genetic testing was performed revealing a mutation in the CSNK2A1 gene causative of OCNDS. When later tested again to confirm the urea cycle disorder, the test came back normal. She was being treated for this disorder but discontinued the treatment upon this finding.

The authors also reviewed all 33 previously reported OCNDS cases, ranking the relevance of specific symptoms. Developmental delay was reported in all cases, although with great variability in severity. Most patients displayed speech delays, intellectual disability, and dysmorphic facial features. Only 9/31 patients included in this portion of the review were determined to have had seizures, and this patient is the only to have been reported to have two different kinds of seizures. This report displays the great variability present between OCNDS patients.