The first Japanese case of Charcot-Marie-Tooth disease type 4H with a novel FGD4 c.837-1G>A mutation

Charcot-Marie-Tooth disease type 4H (CMT4H) is an autosomal recessive demyelinating neuropathy. It presents as infancy or early childhood-onset neuropathy associated with FGD4 mutations. Clinically it causes predominantly distal muscle weakness. On nerve biopsy examination, myelin outfoldings are seen. The previous case reports have been from regions bordering the Mediterranean, as well as a family from Northern Ireland. This paper presents the detailed clinical course of the first reported case of CMT4H in a Japanese woman. The patient showed mild weakness without scoliosis and a severe sensory disturbance; her functional impairment was less severe than the previously published cases. In addition, a novel homozygous FGD4 c.837-1G>A mutation was identified in this patient.