A patient with both Charcot-Marie-Tooth disease (CMT 1A) and mild spinal muscular atrophy (SMA 3).

In the present study, we report a single Polish SMA family in which the 17p11.2-p12 duplication causative for the Charcot-Marie-Tooth type 1A disease (CMT1A) was found in addition to a deletion of exons 7 and 8 of the SMN1 gene. A patient harboring both SMA and CMT1A mutations manifested with SMA3 phenotype and foot deformity. Her electrophysiological testing showed chronic neurogenic changes in proximal muscles that are typical for SMA, but also slowed conduction velocity in motor and sensory fibers that is typical for demyelinating neuropathy.