Asian hereditary neuropathy patients with peripheral myelin protein-22 gene aneuploidy

Japanese hereditary neuropathy with liability to pressure palsy (HNPP) patients have a deletion of one peripheral myelin protein-22 (PMP22) gene region in distal chromosome band 17p11.2 as do Caucasian patients. Japanese and Asiatic Indian CMT1A patients have a PMP22 gene duplication that results in Charcot-Marie-Tooth disease type IA (CMT1A; HMSNIA) in patients of European and Middle Eastern ancestry. About 70% of Japanese CMT1 patients have a PMP22 duplication as do Caucasians, while Japanese CMT1B, CMT2 and Dejerine-Sottas patients do not have PMP22 gene region aneuploidy. Although HNPP and CMT1A genotypes are generated simultaneously by unequal recombination that results in PMP22 gene aneuploidy in each daughter cell, only 3 Japanese HNPP probands with PMP22 deletion from a large patient population were referred to a single center compared to 18 referred CMT1A probands with PMP22 duplication. This lower HNPP frequency more likely reflects lower HNPP reproductive fitness than patient ascertainment bias because disease severity and variation in severity is about the same in CMT1A and HNPP patients and because all patients of both types were referred regardless of disease severity. These results, along with an apparently high de novo CMT1A mutation rate, suggest that common ancestors of Japanese, Asian Indians, and Caucasians carried PMP22 geneflanking sequences that enhance unequal crossing over. © 1995 Wiley-Liss, Inc.     

Charcot‐Marie‐Tooth disease type I and related demyelinating neuropathies: Mutation analysis in a large cohort of Italian families

Charcot‐Marie‐Tooth neuropathy type 1 (CMT1), the most common hereditary neurological disorder in humans, is characterized by clinical and genetic heterogeneity. It is caused mainly by a 1.5 Mb duplication in 17p11.2, but also by mutations in the myelin genes PMP22 (peripheral myelin protein 22), MPZ (myelin protein zero), Cx32 (connexin 32; also called GJB1), and EGR2 (early growth response 2). In this study, we have screened 172 index cases of Italian families in which there was at least one subject with a CMT1 diagnosis for the duplication on 17p11.2 and mutations in these genes. Among 170 informative unrelated patients, the overall duplication frequency was 57.6%. A difference could be observed between the duplication frequency in familial cases (71.6%) and that observed in non‐familial cases (36.8%). Among the non‐duplicated patients, 12 were mutated in Cx32, four in MPZ, two in PMP22, and none in the EGR2. In the non‐duplicated cases, the overall point mutation frequency for these genes was 25.0%. We describe the mutations identified, and consider possible genotype–phenotype correlation. Hum Mutat 18:32–41, 2001. © 2001 Wiley‐Liss, Inc.     

13例早发型腓骨肌萎缩症的基因分型研究

目的 探讨早发型腓骨肌萎缩症（CMT）的临床特征及遗传变异分析。方法 以临床诊断为早发型CMT的患儿为研究对象，收集相关临床资料，进行肌电图及CMT相关基因检测并分析。结果 早发型CMT病例共13例，男9例（69%），女4例（31%），平均就诊年龄4.0±2.1岁，其中12例（92%）患儿起病年龄 < 2岁。9例（69%）诊断为CMT1型（其中Dejerine-Sottas综合征6人），1例（8%）为中间型，3例（23%）为CMT2型。13例患儿的基因检测结果显示6例（46%）患儿存在外周髓鞘蛋白22（PMP22）基因重复突变、3例（23%）髓鞘蛋白零（MPZ）基因插入突变及点突变、3例（23%）线粒体融合蛋白2（MFN2）基因点突变、1例（8%）人轻肽神经丝蛋白（NEFL）基因点突变，其中11例（85%）为已知致病突变，2例（15%）为新变异。MPZ基因新变异c.394C > G（p.P132A）评级为"可能致病的"及MFN2基因新变异c.326A > G（p.K109R）评级为"致病的"。结论 早发型CMT以PMP22基因重复突变及MPZ基因突变为主，临床分型以CMT1型为主，其中Dejerine-Sottas综合征占有相当比例。     

黄连多糖中单糖组成的HPLC-MS~n法快速识别

目的:探讨采用HPLC-MS~n法快速识别黄连多糖中的单糖组成。方法:黄连药材经过提取、分离、除蛋白、除色素,最终得到黄连多糖,用2 mol/L的三氟乙酸水解黄连多糖,以1-苯基-3-甲基-5-吡唑啉酮(PMP)作单糖衍生化试剂,利用HPLC-MS~n识别黄连中单糖的组成,并解析其衍生物的裂解规律。结果:通过分析,得到的黄连多糖中含有甘露糖、核糖、鼠李糖、半乳糖醛酸、葡萄糖、半乳糖、阿拉伯糖/木糖、岩藻糖,其中核糖、岩藻糖为首次在黄连多糖中报道的单糖。结论:HPLC-MS~n法对中药多糖组分中的单糖成分进行分析具有重要的指导意义。     

Hereditary neuropathy with liability to pressure palsy in patients under 30 years old: Neurophysiological data and proposed electrodiagnostic criteria

Introduction: In young patients with mononeuropathy who lack family history and precipitating factors, hereditary neuropathy with liability to pressure palsy (HNPP) may be a possibility. Our objective is to propose neurophysiological criteria for HNPP in patients <30 years of age. Methods: We conducted a national multicenter retrospective clinical and neurophysiological study in patients under 30 with genetically confirmed HNPP. Results: All of the 51 patients included in the study had at least 1 demyelinating pattern in 2 asymptomatic nerves, and 3 abnormalities were found in almost 90%, including slowed motor nerve conduction velocity across the elbow in at least 1 ulnar nerve (97.5%), increased distal motor latency (DML) in at least 1 fibular nerve (95.8%), and increased DML in both median nerves (89%). Age influenced DML slightly only in the fibular nerve. Discussion: Dissemination of nerve involvement in HNPP incites to perform a complete nerve conduction study. including bilateral ulnar, fibular, and median nerves. Muscle Nerve 57 : 217–221, 2018     

柱前衍生化UPLC-MS/MS测定12种单糖含量的方法学研究及其应用

建立了1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生化UPLC-MS/MS检测12种单糖的方法,同时对蜜环菌中多糖的单糖组成成分进行了分析。安捷伦ZORBAX RRHD Eclipse Plus C18分析柱(2. 1 mm×100 mm,1. 8μm),95%乙腈(A)和乙酸铵-5%乙腈-水(B)为流动相梯度洗脱,质谱为电喷雾离子源(ESI)接口,采用负离子多反应监测模式(MRM)进行检测。结果表明,基于UPLC-MS/MS所建立的单糖检测方法,12种单糖成分在各自线性范围内线性关系良好(R^2> 0. 990),加样回收率为92. 30%~105. 6%。在蜜环菌样品中,可检测出除阿洛糖外的11种单糖组分。该试验所建立的方法稳健,重复性和准确度高,适用于蜜环菌等的单糖成分的含量测定。     

Hereditary neuropathy with liability to pressure palsies associated with central nervous system myelin lesions

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder most commonly caused by a 1.5-Mb deletion in chromosome 17p11.2 which contains the peripheral myelin protein-22 (PMP22) gene. Mutations resulting in functional loss of one PMP22 gene copy are less frequent. We present a 51-year-old patient with a l.5-Mb deletion in chromosome 17p11.2 who exhibited signs of peripheral as well as central nervous system lesions. He gave a history of recurrent episodes of limb numbness and weakness with spontaneous but incomplete recovery since age 20. His father and two brothers had similar symptoms. Neurological examination revealed signs of multiple mononeuropathy associated with frontal lobe, corticospinal tract and cerebellar dysfunction, as well as signs of initial cognitive impairment. Electrophysiological investigations showed a demyelinating peripheral nerve disease with multiple conduction blocks and conduction disturbances in both optic nerves. Magnetic resonance imaging of the brain revealed multiple subcortical and periventricular foci of myelin lesions. The association of central and peripheral nervous system lesions in this patient indicates a possible role of PMP22 not only in peripheral but also in central nervous system myelin structure.     

鹦鹉热嗜衣原体两对荧光定量PCR引物的应用与比较

针对鹦鹉热嗜衣原体(Cps)的主要外膜蛋白(MOMP)基因和多形态膜蛋白(PMP)基因分别设计引物,建立荧光定量PCR方法,比较两对引物的灵敏度和特异性。试验结果表明,两对引物均可用于Cps检测,在样本中靶标浓度高时,PMP引物的检测灵敏度优于MOMP引物;但前者的扩增效率低于后者,后者更适合用于Cps的实时定量PCR检测。相对定量研究表明国内不同Cps流行株的PMP基因在基因组上的拷贝数可能存在较大差异。     

Blink reflex role in algorithmic genetic testing of inherited polyneuropathies

Introduction: In severely affected inherited polyneuropathy patients, primary demyelination can be difficult to determine by routine extremity limb nerve conduction studies (NCS). Blink reflexes may help classify severe polyneuropathies as either axonal or demyelinating. However, blink reflex studies have not been studied systematically in any genetically confirmed cohort. Methods: Patients with a genetic diagnosis who had undergone blink reflex testing and extremity NCS were identified retrospectively. Blink reflex R1 latency, extremity NCS, and severity were compared. Results: We identified 26 demyelinating and 23 axonal, genetically confirmed cases, including 20 with PMP22 duplications. In 12 (25%), the ulnar CMAP amplitude was ≤0.5 mV making electrophysiological classification difficult. However, the R1‐latency cutoff of >13 ms (demyelinating) robustly classified all patients regardless of severity. Conclusions: We show that blink reflex studies are reliable for identification of inherited demyelinating polyneuropathy regardless of severity and can facilitate algorithmic decisions in genetic testing. Muscle Nerve 55 : 316–322, 2017