Research Explained: Persistent hyperplastic primary vitreous with microphthalmia and coloboma in a patient with Okur-Chung Neurodevelopmental Syndrome

Authors: Hiroaki Murakami, Tomoko Uehara, Yumi Enomoto, Naoto Nishimura, Tatsuro Kumaki, Yukiko Kuroda, Mizuki Asano, Noriko Aida, Kenjiro Kosaki, Kenji Kurosawa.

Publication Date: September 22, 2021

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

Link to article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8832215/

Research Explained Summary:

This case report profiled a 5-year-old OCNDS patient whose distinguishing feature was their ocular symptoms. The patient was initially referred to an eye clinic at one month of age, as he had never opened his eyes. While brain MRI showed no abnormalities, an examination of the eyes revealed a variety of malformations, including bilateral persistent hyperplastic primary vitreous (PHPV), which leaves the patient with extra blood vessels in their eyes, potentially causing vision impairment in the future. The patient also had abnormally small eyes (microphthalmia) and missing tissue in the eye (coloboma).

By age 2, broader developmental delays were evident, including developing head control at 6 months of age, crawling at 16 months, walking at 17 months, and speaking at 24 months. He also displayed various behavioral issues including restlessness and hyperactivity. As a result of this constellation of symptoms, genetic testing was performed, identifying a mutation in the CSNK2A1 gene known as p.Arg107*, indicative of OCNDS. This is only the second report of abnormal eye development in OCNDS and was much more severe than the initial report of a patient who only had retinal abnormalities. The researchers concluded that the wide variability of manifestations of OCNDS and the sparse appearance of ocular symptoms make it difficult to add poor eye development to the list of OCNDS symptoms, although future cases may clarify this potential link.