X-linked adrenoleukodystrophy as an etiological cause of progressive spastic paraplegia: A case report.

X-linked adrenoleukodystrophy is a rare peroxisomal disorder caused by mutations in ABCD1, thereby resulting in impaired β-oxidation of very long-chain fatty acids. Its adult-onset form, adrenomyeloneuropathy, typically presents as progressive spastic paraparesis that mimics hereditary spastic paraplegia. Brain and spinal magnetic resonance imaging findings are often unremarkable, contributing to diagnostic delays and misdiagnosis. Herein, we report the case of a 60-year-old woman who presented with a 10-year history of progressive lower limb stiffness, weakness, and gait disturbance. She was initially diagnosed with hereditary spastic paraplegia and sought a second opinion. Her family history was remarkable for her father, who experienced a chronic gait disturbance of unknown etiology but never received a formal diagnosis. Neurological examination revealed mild weakness and spasticity in the bilateral lower extremities accompanied by bladder dysfunction, whereas magnetic resonance imaging of the brain and spine was normal. Given the relevant family history and presence of urinary symptoms, metabolic testing was performed. Elevated plasma very long-chain fatty acid levels and a pathogenic variant in ABCD1 confirmed the diagnosis of X-linked adrenoleukodystrophy presenting as adrenomyeloneuropathy. This case underscores the need to consider X-linked adrenoleukodystrophy in patients with progressive spastic paraparesis, even in the absence of imaging abnormalities.