Swiss Cheese (SWS) is the Drosophila orthologue of Neuropathy Target Esterase (NTE), a phospholipase that when mutated has been shown to cause a spectrum of disorders in humans that range from intellectual disabilities to ataxia.
Mutations in the PNPLA6 gene have been identified as the cause of hereditary spastic paraplegia and complex forms of ataxia associated with retinal and endocrine manifestations.
Various genes (eg, SPG7, SYNE1, PNPLA6) traditionally rooted in either the ataxia or hereditary spastic paraplegia classification system have now been shown to cause ataxia on the one end of the disease continuum and hereditary spastic paraplegia on the other.