Late-Onset X-linked Adrenoleukodystrophy: A Rare Cause of Progressive Spastic Paraparesis.

X-linked adrenoleukodystrophy (X-ALD) is an uncommon peroxisomal disorder that can manifest in adult women with slowly progressive motor symptoms that often mimic hereditary spastic paraplegia, contributing to delayed diagnosis. We report the case of a 64-year-old woman with a long history of worsening gait impairment who had previously undergone spinal surgery without clinical benefit. She exhibited a spastic paraparesis with upper motor neuron features, and neuroimaging demonstrated white matter abnormalities in the brain with no structural explanation in the spine. Extensive laboratory testing excluded infectious, autoimmune, and metabolic causes. Biochemical evaluation revealed elevated very-long-chain fatty acids, raising suspicion for X-ALD, and genetic testing confirmed a heterozygous ABCD1 c.1849C>T (p.R617C) pathogenic variant. This case highlights the need to consider X-ALD in women presenting with unexplained progressive spastic paraparesis, emphasizing the value of timely biochemical and genetic evaluation to achieve an accurate diagnosis and provide appropriate guidance for affected families.