Akinesia, arthrogryposis, craniosynostosis: a presentation of neonatal myasthenia with fetal onset.

Major akinesia with arthrogryposis and craniosynostosis at birth mimics irreversible disorders of the nervous system of pejorative outcome. In this context, the early detection of anti-acetylcholine fetal receptor antibodies in the mother may allow rapid diagnosis of transient neonatal myasthenia of favorable prognosis.