Department of Neurology, Pusan National University School of Medicine, Yangsan, Kumo-ro 20, Beomo-ri, Mulgum-eup, Yangsan, Gyeongnam 626-770, Republic of Korea.
Muscle Nerve. 2012 Oct;46(4):600-4. doi: 10.1002/mus.23451.
Limb-girdle myasthenia with tubular aggregates (LGM with TAs) is a subtype of congenital myasthenic syndrome caused by recessive mutations of glutamine-fructose-6-phosphate transaminase 1 (GFPT1).
Clinical and neurophysiological assessment was made in a Korean boy who had proximal limb muscle weakness. Findings suggested a diagnosis of congenital myasthenic syndrome.
Muscle biopsy disclosed numerous TAs in muscle fibers, and DNA sequence analysis disclosed 2 novel missense mutations (p.E256Q and p.M499T) in GFPT1. Treatment with oral cholinesterase inhibitors produced a dramatic improvement in muscle strength.
GFPT1 is the key enzyme in the hexosamine biosynthesis pathway, and mutations in GFPT1 cause defective glycosylation in the proteins of the neuromuscular junction. Identification of LGM with TAs among patients with congenital myasthenic syndrome is important because treatment with cholinesterase inhibitors can produce symptomatic improvement.
伴有管聚集的肢体带肌病（LGM 伴 TAs）是一种由谷氨酸-果糖-6-磷酸转氨酶 1（GFPT1）隐性突变引起的先天性肌无力综合征亚型。
对一名患有近端肢体肌无力的韩国男孩进行了临床和神经生理学评估。检查结果提示先天性肌无力综合征的诊断。
肌肉活检显示肌肉纤维中有大量 TAs，DNA 序列分析显示 GFPT1 中有 2 个新的错义突变（p.E256Q 和 p.M499T）。胆碱酯酶抑制剂口服治疗显著改善了肌肉力量。
GFPT1 是己糖胺生物合成途径中的关键酶，GFPT1 突变导致神经肌肉接头蛋白的糖基化缺陷。在先天性肌无力综合征患者中识别出伴有管聚集的肢体带肌病很重要，因为胆碱酯酶抑制剂治疗可以改善症状。
