Hereditary Neuropathy with Liability to Pressure Palsies: A Report of Two Cases

遺傳性壓迫易感性神經病變：兩病例報告

林衢序(Chu-Hsu Lin) ； 羅榮昇(Long-Sun Ro) ； 許宏志(Hung-Chih Hsu) ； 謝煒基(Wei-Chi Hsieh) ； 林智容(Chih-Jung Lin) ； 李建德(Jian-Der Lee)

《台灣復健醫學雜誌》 35卷1期 (2007/03) Pp. 41-47

https://doi.org/10.6315/2007.35(1)06

摘要

遺傳性壓迫易感性神經病變（hereditary neuropathy with liability to pressure palsies，簡稱HNPP）是一自體顯性遺傳的一種自限性、但易復發的壓迫性單一神經病變。患者常因為很輕微的傷害，便在常見的神經易生卡陷的部位(common entrapment sites)發生局部壓迫性神經病灶。這種疾病最常在青少年的階段開始出現症狀。藉由電學診斷可以發現患者有輕度廣泛性去髓鞘神經病變伴隨在常見的神經卡陷部位的發生局部壓迫性神經病變。神經活檢常可以發現有區段性去髓鞘與髓鞘肥厚的情形。此疾病大多是因為人體第17對染色體17p11.2的部位發生了1.5Mb 的缺失，這個部位的遺傳物質包含了周邊髓鞘蛋白22（peripheral myelin protein 22, 簡稱PMP22）的基因。本文敘述了一個罹病的個案其家庭成員的臨床表徵、電學診斷與基因檢查的結果。在五位家庭成員中，其中1位為無症狀基因帶原者，2位為罹病的個案，他們的神經傳導速度皆有全面性降低的情形，並且在常見神經卡陷部位都發生了傳導速度局部減緩或是傳導阻滯(conduction block)的情形。並且3個人都經由基因檢查確定在第17對染色體17p11.2的部位發生Charcot-Marie-Tooth type IA 序列的缺失。本個案研究的結果認為經由臨床的症狀、家族史與電學診斷的發現可以幫助我們診斷HNPP。不過，最後的確診仍須仰賴基因檢查。

關鍵字

神經壓迫症狀 ； 遺傳性神經病變 ； 神經傳導檢查 ； 周邊髓鞘蛋白22 ； 臘腸性神經病變

並列摘要

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal-dominant disorder characterized by self-limited, recurrent compressive mononeuropathies at common entrapment sites precipitated by trivial injuries. This disorder typically develops in early adulthood. Electrodiagnostic studies revealed diffuse mild demyelinating neuropathies with entrapment over common entrapment sites. Nerve biopsies frequently show segmental demyelination and thickening of the myelin sheath which is mostly caused by 1.5 Mb deletion of the 17p 11.2 site containing the peripheral myelin protein 22 (PMP22) gene on the 17(superscript th) chromosome. This report describes the clinical features, electrodiagnostic studies, and genetic studies of a Taiwanese family. Among the 5 members evaluated, 1 latent and 2 symptomatic cases had generally decreased nerve conduction velocities with further focally decreased conduction velocities or conduction blocks at common entrapment sites. Genetic studies demonstrated deletion of the Charcot-Marie-Tooth type IA sequences in 17p 11.2 in all 3 patients. Our case studies suggested that diagnosis of HNPP can be based on clinical suspicion, positive family history, and electrodiagnostic tests; however final confirmation should be based on genetic study.

並列關鍵字

nerve compression syndrome ； hereditary neuropathy ； nerve conduction study ； peripheral myelin protein PMP22 ； tomaculous neuropathy