Pathogenic ZNF319 variant disrupts nuclear localization and transcriptional regulation to cause a novel form of autosomal recessive leukodystrophy.

Leukodystrophies are inherited disorders characterized by progressive degeneration of white matter in the central nervous system. Here, we investigate a previously uncharacterized autosomal recessive leukodystrophy which is associated with the homozygous missense variant in ZNF319 (c.800T>C; p.Phe267Ser) in an 18-year-old male presenting with spasticity, ataxia, cognitive decline, and white matter abnormalities on MRI. The variant was absent in population databases (gnomAD, ClinVar) and predicted to be pathogenic by multiple in silico tools. Molecular dynamics simulations revealed that F267 is a stabilizing residue within a β-strand of the zinc finger domain, forming π-stacking and hydrophobic interactions that are lost upon substitution with serine, leading to structural instability, increased flexibility, and protein unfolding. Despite normal transcript and protein expression, ZNF319-F267S mislocalized to the cytoplasm due to disruption of its bipartite nuclear localization signal (NLS), resulting in impaired interaction with importin α1 (KPNA1). Functional analysis confirmed that the mutation disrupts nuclear transport and prevents transcriptional activation of genes involved in myelination. Protein interaction network and gene ontology analysis highlighted ZNF319's role in transcriptional regulation and its localization in the CHOP-C/EBP transcriptional complex. Expression profiling demonstrated ZNF319 enrichment in oligodendrocytes and white matter regions, correlating with the observed leukoencephalopathy. Our study identifies ZNF319 as a novel gene implicated in human leukodystrophy and highlights how a single-point mutation can compromise nuclear import and transcriptional function, leading to white matter degeneration. These findings expand the genetic landscape of leukodystrophies and provide mechanistic insights into transcriptional regulation in myelin maintenance.