COMT and drug-induced dyskinesia: Sampaio et al. observed that carriers of monoamine oxidase B (MAO-B) (rs1799836) A and AA genotypes and COMT (rs4680) LL genotype suffered more frequently from levodopa-induced-dyskinesia, but also that there is an increased risk of 2.84-fold for male individuals carrying the MAO-B G allele to develop motor complications when treated with higher doses of levodopa (p = 0.04) [23].