Anti-N-methyl-D-aspartate Receptor Encephalitis in Turner Syndrome with 45,X/46,X,idic(X)(p11.4) Mosaics.

A 46-year-old woman with Turner syndrome (TS) (45,X/46,X,idic(X)(p11.4) mosaic) presented with a fever, unresponsiveness, hyperhidrosis, and rigidity approximately one month after episodes of confusion and suicide attempts, prompting a diagnosis of schizophrenia. Cerebrospinal fluid (CSF) showed mild hypercellularity with oligoclonal bands. Brain and abdominal magnetic resonance imaging showed no abnormalities. Bizarre upper-extremity movements and spasms followed the trial administration of acyclovir, and autoimmune encephalitis was suspected. Intensive immunotherapy was initiated, and the symptoms improved. Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis was diagnosed based on the presence of anti-NMDAR antibodies in her spinal fluid. This case represents a rare presentation of anti-NMDAR encephalitis in TS, which is susceptible to autoimmune disease complications.