Variants of autophagy-related gene 5 are associated with neuromyelitis optica in the Southern Han Chinese population.

Neuromyelitis optica (NMO) and multiple sclerosis (MS) are autoimmune demyelinating diseases of the central nervous system. The discovery of NMO immunoglobulin G (NMO-IgG) antibody has improved the clinical definition of NMO. Recently, the autophagy-related genes (ATGs) have been proved to be associated with several autoimmune and inflammation diseases. Increased T cell expression of ATG5 may be correlated with the pathogenesis of inflammatory demyelination in MS. However, the association of ATG5 variants with MS and NMO patients has not been well studied. In this study, five ATG5 variants were genotyped in 144 MS patients, 109 NMO patients and 288 controls in the Han Chinese population. In the cohort of NMO patients, we observed that the CC genotype of rs548234 increased susceptibility to NMO (p = 0.016), while the allele T of rs548234 (p = 0.003) and the allele A of rs6937876 (p = 0.009) acted as protective factors for NMO-IgG positive NMO patients. However, no association was found between ATG5 variants and MS patients. These results indicated that ATG5 variants are associated with NMO but not MS patients, which may provide a clue for further clarifying the autoimmune mechanisms of autophagy-related pathogenesis in NMO.