A Rare Case of Fatty Acid Hydroxylase-Associated Neurodegeneration in a Pakistani Boy With a Homozygous FA2H Variant.

Fatty acid hydroxylase-associated neurodegeneration (FAHN) is an ultra-rare neurological disorder caused by a mutation in the FA2H gene. Defective production of this gene leads to abnormal myelin formation, which subsequently causes neurodegeneration and brain iron accumulation. This case report presents the case of a 7-year-old boy from Pakistan who was born to consanguineous parents. The initial symptom presented at two and a half years of age with seizures. His clinical course progressively worsened, manifesting as gait disturbances, dystonia, and regression of milestones. By the age of 7, he was unable to walk without support. On examination, the patient had a spastic diplegic gait with plantarflexion contracture in both lower limbs. Brain Magnetic Resonance Imaging (MRI) findings reported abnormal T2-weighted hyperintensities, predominantly involving the parietal white matter, which is suggestive of FAHN. Finally, the diagnosis was confirmed by genetic analysis with the identification of a strong homozygous c.704G>A (p.Arg235 His) missense mutation in the FA2H gene.