| Summary: | Biallelic mutations in the <i>CYP7B1</i> gene lead to spastic paraplegia-5 (SPG5). We report herein the case of a patient whose clinical symptoms began with progressive lower limb spasticity during childhood, and who secondly developed amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) at the age of 67 years. Hereditary spastic paraplegia (HSP) gene analysis identified the compound heterozygous mutations c.825T>A (pTyr275*) and c.1193C>T (pPro398Leu) in <i>CYP7B1</i> gene. No other pathogenic variant in frequent ALS/FTD causative genes was found. The <i>CYP7B1</i> gene seems, therefore, to be the third gene associated with the phenoconversion from HSP to ALS, after the recently described <i>UBQLN2</i> and <i>ERLIN2</i> genes. We therefore expand the phenotype associated with <i>CYP7B1</i> biallelic mutations and make an assumption about a link between cholesterol dyshomeostasis and ALS/FTD.
|
|---|