De Novo Truncating Variants in ZNF865 Cause a Novel Neurodevelopmental Disorder

Despite significant knowledge advances in recent decades, the role of most protein-coding genes in human disease remains incompletely understood. Exome sequencing continues to improve our understanding by elucidating novel genotype-phenotype associations. Across multiple healthcare centers, either exome or genome sequencing was performed in 18 patients with shared features of global developmental delay, hypotonia, and dysmorphisms. De novo, truncating variants in ZNF865 were identified in all 18 patients, with all but one clustered toward the C-terminus. Four variants were seen more than once in unrelated patients. No disease-causing variants were identified in other genes that would explain the patients' phenotypes. Little is known of the function of ZNF865, which belongs to the poly-zinc finger family of proteins that contain a large array of tandem C2H2 zinc finger DNA binding domains. Our findings suggest that protein-truncating variants in this gene lead to intellectual disability with a recognizable phenotypic pattern.