Two cases of peripheral neuropathy beginning in childhood are reported. Both had features suggestive of HMSN with pes cavus and kyphoscoliosis. Familial history of HMSN type I was present in 9 members of the kinship in case 1. In case 2, a mild neuropathy without pes cavus was present in the father. Case 1 developed four relapses of ascending sensory-motor deficit with conduction blocks suggestive of a superimposed chronic inflammatory polyneuropathy (CIP) which improved under prednisone. In case 2, the course was progressive with a severe proximal and distal motor weakness and sensitive disturbances. CSF protein concentration was high. Nerve biopsy showed rare onion bulbs and intense demyelination. These results joint to the unspecificity of the father's neuropathy are consistent with a probable childhood. CIP which improved under prednisone. These two cases indicated that in some patients with unusual symptoms for HMSN, prednisone should be considered and that the physiopathology of these neuropathies is probably heterogeneous.