P/LP variants in genes typically associated with HSP were a frequent finding in this cohort (13.5% of diagnoses, SPAST (two cases), TUBB4A, KIDINS220 and ALDH3A2), confirming previous observations of the clinical overlap between early onset HSP and CP12,37,38 and adding to the growing list of HSP genes contributing to the genetic landscape of CP36,39. This evidence concerns the gene CYP1A2 and hereditary spastic paraplegia.