Inserm, U975, Centre de recherche de l'Institut du Cerveau et de la Moelle Épinière (CRICM), Groupe hospitalier Pitié-Salpêtrière, Paris, France; Université Pierre et Marie Curie Paris 6, UMRS975, Paris, France; CNRS, UMR7225, Paris, France; Ecole Pratique des Hautes Etudes, Paris, France.
Neuromuscul Disord. 2013 Dec;23(12):998-1009. doi: 10.1016/j.nmd.2013.07.005. Epub 2013 Sep 4.
Schwartz-Jampel syndrome (SJS) is a recessive disorder with muscle hyperactivity that results from hypomorphic mutations in the perlecan gene, a basement membrane proteoglycan. Analyses done on a mouse model have suggested that SJS is a congenital form of distal peripheral nerve hyperexcitability resulting from synaptic acetylcholinesterase deficiency, nerve terminal instability with preterminal amyelination, and subtle peripheral nerve changes. We investigated one adult patient with SJS to study this statement in humans. Perlecan deficiency due to hypomorphic mutations was observed in the patient biological samples. Electroneuromyography showed normal nerve conduction, neuromuscular transmission, and compound nerve action potentials while multiple measures of peripheral nerve excitability along the nerve trunk did not detect changes. Needle electromyography detected complex repetitive discharges without any evidence for neuromuscular transmission failure. The study of muscle biopsies containing neuromuscular junctions showed well-formed post-synaptic element, synaptic acetylcholinesterase deficiency, denervation of synaptic gutters with reinnervation by terminal sprouting, and long nonmyelinated preterminal nerve segments. These data support the notion of peripheral nerve hyperexcitability in SJS, which would originate distally from synergistic actions of peripheral nerve and neuromuscular junction changes as a result of perlecan deficiency.
施瓦茨-詹佩尔综合征（SJS）是一种肌肉活性亢进的隐性疾病，由底膜蛋白聚糖—— 硫酸乙酰肝素蛋白聚糖（perlecan）基因的功能缺失性突变引起。对小鼠模型的分析表明，SJS 是一种先天性远端周围神经兴奋性过高的疾病，由突触乙酰胆碱酯酶缺乏、神经末梢不稳定伴前髓鞘化以及细微的周围神经变化引起。我们研究了一位 SJS 成年患者，以在人类中研究这一说法。在患者的生物样本中观察到由于功能缺失性突变导致的 perlecan 缺乏。电神经生理学显示正常的神经传导、神经肌肉传递和复合神经动作电位，而沿着神经干的多种外周神经兴奋性测量均未检测到变化。肌电图检测到复杂的重复放电，没有任何神经肌肉传递失败的证据。含有神经肌肉接头的肌肉活检显示形成良好的突触后元件、突触乙酰胆碱酯酶缺乏、突触沟槽失神经支配伴末梢发芽再支配，以及长非髓鞘节前神经段。这些数据支持 SJS 周围神经兴奋性过高的观点，这将起源于远端，是由于 perlecan 缺乏引起的周围神经和神经肌肉接头变化的协同作用。
