Biallelic Variants in SLC27A3 Cause a Complex Form of Neurodegeneration with Brain Iron Accumulation

BackgroundComplex lipid metabolism is one of the main biological pathways disrupted in neurodegeneration with brain iron accumulation (NBIA). SLC27A3 gene encodes for the very long‐chain acyl‐CoA synthetase 3, an acyl‐CoA ligase that activates long and very long‐chain fatty acids.ObjectiveWe report on a 19‐year‐old patient with an NBIA pattern harboring a homozygous, nonsense SLC27A3 variant.MethodsSLC27A3 variants were identified using whole exome sequencing (WES). Their impact on protein function was assessed in patient fibroblasts using Western blot analysis, aerobic metabolism analysis, and fatty acid trafficking assays.ResultsThe patient presented with progressive ataxia, neuropathy, optic atrophy, cognitive deterioration, mood disorder, and brain iron accumulation. WES unraveled the homozygous c.1138C>T, p.(Arg380Ter) variant in the SLC27A3 gene. Functional studies showed that proband's variants eliminate protein expression, severely impair mitochondrial respiration, and disrupt lipid turnover.ConclusionOur results suggest that SLC27A3 biallelic nonsense variant may represent a novel cause of NBIA. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.