CSNK2A1 and Okur-Chung neurodevelopmental syndrome: Since phenotypes across neurodevelopmental disorders are heterogeneous and can range in severity, whole exome/genome sequencing has facilitated diagnosis and subsequent discovery of genotype–phenotype relationships for genetic disorders (Savatt and Myers, 2021; van der Sanden et al., 2023) including the identification of Okur-Chung Neurodevelopmental Syndrome (OCNDS), an ultra-rare genetic disorder caused by heterozygous mutations in the CSNK2A1 gene encoding protein casein kinase 2 alpha subunit 1 (Okur et al., 2016).