Abstract：
Biotinidase deficiency (BTD) is a treatable, inherited metabolic disorder commonly characterised by alopecia, dermatitis, seizures and developmental delay. It can also manifest as optic neuritis and myelitis; however, these are infrequently described in the literature. We report three cases who presented with quadriplegia and vision loss, initially managed as neuromyelitis optica spectrum disorder (NMOSD), based on neuroimaging findings. Two of them initially responded to immune therapy but relapsed after a few months, while one case showed no clinical improvement with immune therapy. The clinical presentation and neuroimaging findings in all three cases were consistent with NMOSD, leading to a delayed diagnosis of BTD. Antiaquaporin4 and antimyelin oligodendrocyte glycoprotein antibodies were negative in all patients. Urine organic acids reported raised markers of biotinidase or holocarboxylase synthase deficiency. Two of them had a dramatic response to biotin supplementation, showing significant improvement in motor function and vision.
摘要：
生物素酶缺乏症(BTD)是一种可治疗的，遗传性代谢紊乱通常以脱发为特征，皮炎,癫痫发作和发育迟缓。它也可以表现为视神经炎和脊髓炎;然而，这些在文献中很少描述。我们报告了三例四肢瘫痪和视力丧失的病例，最初管理为视神经脊髓炎谱系障碍（NMOSD），基于神经影像学的发现。其中两个最初对免疫疗法有反应，但几个月后复发，而1例患者经免疫疗法无临床改善。3例患者的临床表现和神经影像学表现均符合NMOSD,导致BTD的延迟诊断。所有患者的Antiaquaporin4和抗髓鞘少突胶质细胞糖蛋白抗体均为阴性。尿液有机酸报告了生物素酶或全羧化酶合酶缺乏症的标志物。其中两个人对生物素补充有戏剧性的反应，在运动功能和视力方面显着改善。
