Prevalence [15], [16] and incidence [16], [25] of peripheral neuropathy have also been reported to be higher in patients with AIDS than among non-AIDS patients; shorter time to diagnosis has been observed in patients with history of AIDS diagnosis [17]; and higher risk of progression of established distal symmetric polyneuropathy, measured as an increase of the total neuropathy score, has been associated with reduction in CD4 levels [29]. This evidence concerns the gene CD4 and peripheral neuropathy.