Scaphocephaly as a Novel Phenotypic Feature of WDR83OS-Related Neurodevelopmental Disorder: A Case Report With a Novel Variant and Literature Review.

WDR83OS-related neurodevelopmental disorder is a rare autosomal recessive condition characterized by developmental delay, dysmorphic features and variable hepatic involvement, particularly hypercholanaemia. Here, we report a female patient presenting with global developmental delay, syndromic facial features and scaphocephaly due to sagittal craniosynostosis, representing a previously unreported phenotypic feature. The patient was born to consanguineous parents and exhibited delayed motor and language milestones. Physical examination revealed characteristic dysmorphic features, whereas routine laboratory findings, including liver function tests, were within normal limits. Serum bile acid levels were not assessed. Cranial imaging confirmed sagittal craniosynostosis. Whole exome sequencing identified a novel homozygous nonsense variant in WDR83OS, classified as likely pathogenic according to ACMG criteria. No additional candidate variants, including those associated with craniosynostosis, were detected. This case possibly expands the phenotypic spectrum of WDR83OS-related disorder by identifying scaphocephaly as a novel feature. Our findings highlight the importance of comprehensive genomic evaluation in syndromic neurodevelopmental disorders and suggest that WDR83OS should be considered in the differential diagnosis of patients with craniosynostosis and developmental delay, even in the absence of overt hepatic involvement.