In addition, we (the Meisler group) have identified recessive FIG4 mutations in patients with hereditary peripheral neuropathy (Charcot-Marie-Tooth Disease type 4J) [16-18] and motor neuron disease (amyotrophic lateral sclerosis, or ALS) [19]. The gene discussed is FIG4; the disease is Charcot-Marie-Tooth disease type 4J.