Shimazaki Haruo, Sakoe Kumi, Niijima Kenji, Nakano Imaharu, Takiyama Yoshihisa
Division of Neurology, Department of Internal Medicine, Jichi Medical University, Yakushiji 3311-1, Shimotsuke, Tochigi 329-0498, Japan.
J Neurol Sci. 2007 Apr 15;255(1-2):87-9. doi: 10.1016/j.jns.2007.02.002. Epub 2007 Mar 8.
The authors describe an unusual case of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) without leg spasticity, which is a core clinical feature of ARSACS. This is the second family with a spasticity-lacking phenotype in ARSACS. A peripheral nerve conduction study disclosed decreases in motor and sensory nerve conduction velocities with the disease progression. Although the leg spasticity is reported to become progressively worse during the disease and is prevalent in older patients, we first observed that the symptom had disappeared, probably due to the progressive peripheral nerve degeneration in the disease course. Thus, we should analyze the SACS gene even in cases of early-onset cerebellar ataxia without spasticity. The patient had a novel homozygous 2-base pair deletion mutation (c.5988-9 del CT) of the SACS gene, but the genotype was different from that in our first family of this phenotype. A further genotype-phenotype correlation study is required to clarify the molecular mechanism underlying 'sacsinopathies'.
作者描述了一例罕见的常染色体隐性遗传性夏尔勒维-萨格奈痉挛性共济失调(ARSACS)病例,该病例无腿部痉挛,而腿部痉挛是ARSACS的核心临床特征。这是ARSACS中第二个出现无痉挛表型的家族。一项周围神经传导研究显示,随着疾病进展,运动和感觉神经传导速度降低。尽管据报道腿部痉挛在疾病过程中会逐渐加重,且在老年患者中普遍存在,但我们首次观察到该症状已消失,这可能是由于病程中周围神经的进行性退化所致。因此,即使是早发性无痉挛性小脑共济失调病例,我们也应分析SACS基因。该患者的SACS基因存在一种新的纯合2碱基对缺失突变(c.5988-9 del CT),但其基因型与我们首个具有此表型的家族不同。需要进一步进行基因型-表型相关性研究,以阐明“sacsinopathies”背后的分子机制。