WASHC5 and hereditary spastic paraplegia: KIAA0196 is mutated in pure AD-HSP (SPG8) patients (Valdmanis et al. 2007), but also in complex cases in which the spasticity decreased upon levodopa treatment (Bettencourt et al. 2013), and recently a homozygous splice site mutation leading to exon 27 skipping was involved in Ritscher–Schinzel syndrome, a developmental syndrome with craniofacial abnormalities, congenital heart defects and cerebellar brain malformations (Elliott et al. 2013).