强直性肌营养不良3个家系26例患者白内障发病的特征

背景:白内障并不是强直性肌营养不良必须症状,但它可以是强直性肌营养不良患者早期甚至惟一的临床体征,分子诊断可作为强直性肌营养不良的诊断提供重要依据。目的:分析上海松江地区强直性肌营养不良3个家系26例患者与白内障发病的特征。设计:家系系谱分析。单位:解放军第二军医大学长海医院神经内科。对象:选择2001-05/2003-08在解放军第二军医大学长海医院神经内科收治的3个强直性肌营养不良家系共26例初步诊断或可疑强直性肌营养不良患者为观察对象,年龄7～71岁,其中13例患者均符合《实用神经病学》拟定的临床诊断标准。另13例有部分或轻度强直性肌营养不良症状与(或)体征,为可疑强直性肌营养不良患者。方法:①分别对受检者抽取1mL静脉血按常规法提取DNA,根据强直性肌营养不良的分子诊断标准(CTG三核苷酸重复数80～3350次),长模板扩增PCR法检测CTG重复数。②采用裂隙灯检查患者晶状体观察白内障发病情况,并分析强直性肌营养不良与白内障发病的关系。主要观察指标:①CTG重复数。②强直性肌营养不良患者与白内障发病的关系。结果:26例患者中,除1例为不孕症患者被排除,其余25例患者均进入结果分析。①受检者中25例患者符合强直性肌营养不良的分子诊断标准(CTG三核苷酸重复数80～3350次)。另1个体CTG重复数为13次,临床为不孕症患者,属正常个体。17例白内障患者CTG重复数平均为(2380±80)次,而8例无白内障的强直性肌营养不良患者其CTG重复数平均为(2298±105)次,两者间比较差异无显著性意义(P>0.05)。②17例白内障患者主要表现为晶状体呈彩虹色浑浊或后极部皮质蓝色浑浊。其中8例患者白内障为强直性肌营养不良惟一的早期表现,其CTG重复数均高于正常值。结论:强直性肌营养不良家系中,当特征性的白内障作为强直性肌营养不良患者主要甚至惟一的临床体征时,将为强直性肌营养不良的早期诊断提供重要临床依据。

Characteristics of cataract in 26 patients with myotonic dystrophy from 3 pedigrees

BACKGROUND:Cataract is not the necessary symptom for myotonic dystrophy(DM).But it may be the early and even only clinical symptom of DM.Molecular diagnosis can provide the important evidence for the diagnosis of DM.OBJECTIVE:To explore the characteristics of cataract in 26 patients with myotonic dystrophy of 3 pedigrees from Shanghai Songjiang area.DESIGN:Analysis on the Genealogy of Pedigree.SETTING:Department of Neurology,Shanghai Changhai Hospital.PARTICIPANTS:Twenty-six patients of 3 pedigrees,aged 7 to 71 years old,which were preliminarily diagnosed as DM patients or were suspicious DM patients,admitted to Department of Neurology,Shanghai Changhai Hospital between May 2001 and August 2003,were recruited in this study.Among the involved patients,13 corresponded to the clinical diagnosis standard from Practical Neurology,and the other 13 patients have adverse symptoms and (or) body signs of partial or mild DM,suspecting with DM patients.METHODS:①Peripheral blood of 1 mL was taken and genome DNA was extracted.By using a thermocycler,a polymerase chain reaction (PCR) was carried out to examine the CTG repeats according to criteria of molecular diagnosis (CTG repeats from 80-3350).②In addition,slit-lamp examination for specific lens opacity was carried out and the association between DM and cataract was analyzed.MAIN OUTCOME MEASURES:①CTG trinucleotide repeat numbers.②Association between DM and cataract.RESULTS:Of the 26 patients,25 participated in the final analysis except 1 who suffered from sterility clinically.①25 patients were consistent with the molecular diagnostic criteria of DM (CTG repeats from 80-3 350).The remaining 1 with CTG repeats of 13 was clinically sterility and therefore belonged to the normal individual.The (CTG)n triplet repeats of 17 patients with cataract were 2380±80,while 8 patients with cataract were 2298±105(P＞0.05).②Cataract was characterized as iridescent lens opacity or blue posterior cortical lens opacity in 17 patients.Among the 17 patients,cataract in 8 patients was the only early clinical sign whose(CTG) n triplet repeats were higher than the normal ones.CONCLUSION:In the pedigrees with DM patients,characteristic cataract,as a main and even only early clinical sign,will provide important clinical evidence for the early diagnosis of DM.