PIK3C2A and Guillain-Barre syndrome, familial: COVID-19: coronavirus disease 2019; GBS: Guillain-Barré syndrome; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; AMAN: acute motor axonal neuropathy; AMSAN: acute motor and sensory axonal neuropathy; CIM: critical illness myopathy; CPK: creatine phosphokinase; ICU: intensive care unit; CSF: cerebrospinal fluid; MFS: Miller Fisher syndrome; AIDP: acute inflammatory demyelinating polyradiculopathy