A form of Guillain-Barre syndrome (GBS) that occurs in persons or families with a genetic predisposition to the acute or chronic forms of GBS. Note that GBS is considered to be a complex multifactorial disorder with both genetic and environmental factors, and families with clear Mendelian inheritance have been rarely reported: a mutation in the PMP22 gene (601097) on chromosome 17 was identified in a single family with the acute (AIDP) and chronic (CIDP) forms of inflammatory demyelinating polyneuropathy. Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic monophasic, progressive or relapsing symmetric sensorimotor disorder characterized by progressive muscular weakness with impaired sensation, absent or diminished tendon reflexes and elevated cerebrospinal fluid (CSF) proteins.