Familial, demyelinating sensory and motor polyneuropathy with conduction block.

Both multifocal, demyelinating features and prednisone responsiveness are rare in Charcot-Marie-Tooth (CMT) disease. We report a mother and son with a prednisone-responsive, multifocal, demyelinating, predominantly sensory polyneuropathy that was associated with an isoleucine92valine polymorphism of lipopolysaccharide-induced TNF-alpha factor (LITAF). The mother had a multifocal, acquired, demyelinating sensory and motor polyneuropathy (MADSAM)-like presentation. The son developed left peroneal neuropathy during acute Lyme disease with a subsequent relapsing, MADSAM-like illness, despite antibiotic treatment. Both shared prednisone responsiveness and multifocal, demyelinating features electrophysiologically. MADSAM may be familial (FaDSAM) and respond to prednisone.