%0 Case Reports
%T Anti-MOG antibody encephalitis mimicking neurological deterioration in a case of Rett syndrome with MECP2 mutation.
%A Tani H
%A Ishikawa N
%A Kobayashi Y
%A Yamaoka S
%A Fujii Y
%A Kaneko K
%A Takahashi T
%A Kobayashi M
%J Brain Dev
%V 40
%N 10
%D Nov 2018
%M 30227938
%F 2.272
%R 10.1016/j.braindev.2018.06.011
%X <B>BACKGROUND: </B>Rett syndrome (RTT) is a neurodevelopmental disorder primarily caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene, resulting in developmental regression after normal development during infancy. Transient presentation of many autistic features is also commonly seen in RTT. Anti-myelin oligodendrocyte glycoprotein (MOG)-antibody encephalitis is an acquired relapsing demyelinating syndrome characterized by a variety of neuroinflammatory symptoms. Here, we report a case of anti-MOG antibody encephalitis in a patient with genetically confirmed RTT, which mimicked many of the features of RTT.<BR><B>METHODS: </B>A three-year-old girl presented with subacute verbal and motor dysfunction, along with involuntary movements and marked irritability. Magnetic resonance imaging (MRI) revealed extensive white matter lesions, with anti-MOG antibodies detected in the serum and cerebrospinal fluid, resulting in an initial diagnosis of anti-MOG antibody encephalitis. However, additional testing of the MECP2 gene was performed in response to persistent involuntary hand movements in combination with progressive verbal and motor deterioration. Sequencing analysis revealed a known pathogenic mutation in MEPC2, indicating a concurrent diagnosis of RTT.<BR><B>CONCLUSIONS: </B>Both RTT and anti-MOG antibody encephalitis are rare conditions. Similarities in disease presentation suggest that anti-MOG antibody encephalitis may mimic many of the symptoms of RTT.