SPG7 and Cognitive impairment: The complex phenotype of the SPG7 is associated with upper limb involvement, optic nerve involvement and cognitive deficit.6 VanGassen Kl et al showed that a null mutation was associated with the co occurrence of cerebellar ataxia, a missense mutation of exon 10 resulted in predominant optic nerve atrophy.10 However our cohort was too small to draw any such conclusion.