SPG7 and hereditary spastic paraplegia: To date, the main argument supporting a dominant inheritance of some variants is the description of four families with patients with two mutations having an affected relative carrying only one mutated allele and confirmed by Sanger sequencing.17, 18, 19 Moreover, at least 10 apparently dominant HSP families have been reported, in which the parents of index patients with two mutations in trans were also affected, although their carrier status was not confirmed by Sanger sequencing.20 However, a full screening of SPG7 in heterozygous affected relatives was not undertaken in any of these works.