Preliminary study on the association of AQP4 promoter polymorphism with anti-aquaporin-4 antibody positivity in Southern Han Chinese patients with idiopathic demyelinating disorders of central nervous system

Abstract

ObjectivesTo identify the association of aquaporin-4 (AQP4) promoter polymorphism with the presence of anti-aquaporin-4 antibody (AQP4-Ab) in Southern Han Chinese patients with idiopathic demyelinating disorders of central nervous system. MethodsEighteen neuromyelitis optica (NMO), thirty-eight conventional MS (CMS), thirteen recurrent myelitis (RM), six recurrent optic neuritis (RON) patients and thirty-nine matched controls were enrolled. Polymorphisms of AQP4 promoters 0 and 1 were determined by sequencing-based typing. ResultsFourteen polymorphism loci were observed in AQP4-promoter 0, while the six ones were observed in AQP4-promoter 1. Among them, the frequency of polymorphism at position −1003bp (A-G) of AQP4-promoter 0 in AQP4-Ab-positive patients was significantly higher than that in AQP4-Ab-negative patients and controls (former: 13/18 vs 20/45, P=0.046; latter: 13/18 vs 10/39, P=.001). The frequency of polymorphism at position between −401bp and −400bp (C inserted) of AQP4-promoter 1 in AQP4-Ab-positive and -negative patients was significantly higher than that in controls (former: 5/16 vs 0/28, P=0.008; latter: 8/38 vs 0/28, P=0.027). ConclusionsPolymorphism at position −1003bp (A-G) of AQP4-promoter 0 is associated with the presence of anti-AQP4 antibody. Genetic variation in AQP4 may account for the susceptibility to AQP4-Ab-positive NMO and NMO spectrum disorders in Southern Han Chinese population.