Abstract:

GNE myopathy is a rare and mildly progressive autosomal recessive myopathy caused by GNE mutations. Respiratory dysfunction has not been reported in GNE myopathy patients. In this study, we retrospectively reviewed the respiratory function of 39 severely affected GNE myopathy patients (13 men, 26 women) from medical records, and compared these parameters with various other patient characteristics (e.g., GNE mutations, age at onset, creatine kinase levels, and being wheelchair-bound) for correlations. The mean % forced vital capacity [FVC] was 92 (26) (range, 16-128). In 12/39 (31%) patients, %FVC was <80%. Of these 12 patients, 11 (92%) were entirely wheelchair-dependent. These patients exhibited significantly earlier onset (20 [4] vs. 30 [8] years, p<0.001) and lower creatine kinase levels (56 [71] vs. 279 [185] IU/L) than patients with normal respiratory function. Two patients exhibited severe respiratory failure and required non-invasive positive pressure ventilation. Patients with a homozygous mutation in the N-acetylmannosamine kinase domain exhibited lower %FVC, while only one compound heterozygous patient with separate mutations in the uridinediphosphate-N-acetylglucosamine 2-epimerase and the N-acetylmannosamine kinase domains had respiratory dysfunction. Our results collectively suggest that GNE myopathy can cause severe respiratory failure. Respiratory dysfunction should be carefully monitored in patients with advanced GNE myopathy characterized by early onset and homozygous homozygous mutations in the N-acetylmannosamine kinase domain.

日本語要旨:

GNEミオパチー患者における呼吸機能低下を39名の患者(男性13名、女性26名)について診療録を後方視的に検討した。％努力肺活量(%FVC)の平均値は92であったが、12名(31％)の患者で%FVCが80％未満であった。これら12名の患者のうち11名(92%)は車椅子を使用していた。これらの患者は、平均10年早期発症であり、クレアチンキナーゼ値が呼吸機能正常の患者よりも低かった(56 vs 279)。2例は重症の呼吸不全を呈しており非侵襲的陽圧換気が必要としていた。N-アセ チルマンノサミンキナーゼドメインにホモ接合型変異を有する例は%FVCが低い傾向にあった。