GNE myopathy: A prospective natural history study of disease progression

• DOI: 10.1016/j.nmd.2014.02.008
• Publication Date: 2014-02-28T12:31:15Z
• Authors: Madoka Mori-Yoshi...; Yasushi Oya; Hiroyuki Yajima; Naohiro Yonemoto; Yoko Kobayashi; Yukiko K. Hayashi; Satoru Noguchi; Ichizo Nishino; Miho Murata
• Keywords: Adult; Male; Adolescent; Hand Strength; DNA Mutational Analysis; Walking; Middle Aged; Motor Activity; Respiratory Function Tests; 3. Good health; Distal Myopathies; Disability Evaluation; Young Adult; 03 medical and health sciences; 0302 clinical medicine; Multienzyme Complexes; Heart Function Tests; Disease Progression; Humans; Female; Muscle Strength; Prospective Studies; Follow-Up Studies

Mutations in the glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase gene cause GNE myopathy, a mildly progressive autosomal recessive myopathy. We performed a prospective natural history study in 24 patients with GNE myopathy to select evaluation tools for use in upcoming clinical trials. Patient clinical conditions were evaluated at study entry and one-year follow-up. Of the 24 patients, eight (33.3%) completed a standard 6-min walk test without assistance. No cardiac events were observed. Summed manual muscle testing of 17 muscles, grip power, and percent force vital capacity (%FVC) were significantly reduced (p<0.05), and scores for 6-min walk test and gross motor function measure were decreased (p<0.1) after one year. The decrement in %FVC was significant among non-ambulant patients, whereas the decrement in grip power tended to be greater among ambulant patients. The 6-min walk test, gross motor function measure, manual muscle testing, grip power, and %FVC reflect annual changes and are thus considered good evaluation tools for clinical trials.