 MeCP2 polymorphisms have been reported so far in European-derived and Asian lupus patients.The genetic loss of MECP2 has been identified as changing the properties of cells in the locus ceruleus the exclusive source of noradrenergic innervation to the cerebral cortex and hippocampus.Researchers have concluded that "Because these neurons are a pivotal source of norepinephrine throughout the brainstem and forebrain and are involved in the regulation of diverse functions disrupted in Rett syndrome, such as respiration and cognition, we hypothesize that the locus ceruleus is a critical site at which loss of MECP2 results in CNS dysfunction."