Mutations in neuropathy target esterase (NTE/PNPLA6) are responsible for autosomal recessive HSP (SPG39) (Rainier et al., 2008), but also other neurological syndromes combining ataxia, spasticity, retinal degeneration, and/or hypogonadism (Synofzik et al., 2014). This evidence concerns the gene PNPLA6 and retinal degeneration.