散发性克-雅病PrP基因129密码子基因型与临床表型14例研究

目的：探讨散发性克－雅病（Creutzfeldt-Jakob disease,CJD)PrP基因129位点密码子基因型与临床表型的关系。方法：对14例散发性CJD患者进行PrP基因129例密码子的检测，并与临床表现进行了分析。结果：（1）根据诊断标准，14例散发性CJD中8例诊断为肯定CJD，6例诊断为很可能CJD。（2）8例诊断肯定CJD组中，PrP基因129例位点密码子为甲硫氨酸纯合型6例，甲充氨酸／缬氨酸2例，6例诊断很可能CJD组的PrP基因129密码子均为甲硫氨酸纯合型。（3）12例PrP基因129位点为甲硫氨酸纯合型的患者以认知障碍起病8例，共济失调1例；视觉障碍2例；肌阵挛1例，病程最长20个月，最短2．5个月，病程中有癫痫5例，肌阵挛6周，视觉障碍6例。7例有典型周期性同步放电（PSD）脑电改变。（4）2例甲硫氨酸／缬氨型患者均以共济失调起病。2个月后才出现痴呆，病理程分析为16个月和20个月，均无典型的PSD。（2）本组散发性CJDPrP基因129位点密码子甲硫氨酸／甲硫氨酸，甲硫氨酸／缬氨酸，分布比例与日本相同，但与西方不同，而且没有缬氨酸纯合型。

Studies on codon 129 genotype of PrP gene and phenotypic features of sporadic Creutzfeldt-Jakob disease in China

Objective To investigate the relationship between polymorphism at codon 129 of prion protein gene and the phenotypic features of sporadic Creutzfeldt Jakob disease(CJD)in China Methods The prion protein genotype of 14 cases with sporadic CJD were tested and clinical data were analysed Results (1) 8 cases with definite CJD and 6 cases with probable CJD were diagnosed depending on diagnostic criteria (2) Of the 8 definite CJD cases,6 were homozygous for methionine at codon 129, 2 cases were methionine/valine at codon 129,while all the probable CJD cases were methionine homozygotes (3) There were four group symptoms at onset in 12 cases with methionive homozygous at codon 129: cognitive and mental impairment as first symptom in 8 cases,ataxia in 1 case,blurred sight in 2 cases,myoclonus in 1 case;during illness there were epilepsy in 5 cases,myoclonus in 6 cases,blurred sight in 6 cases,PSD in 7 cases The longest illness duration was 20 months,and the shortest was two and a half months (4) Ataxia was the first symptoms in 2 cases with metionine/ valine at codon 129 The illness duration was 6 and 20 months,and there was no PSD (5) Spongyform degeneration in different degree and neuronal loss were seen in the 8 cases with definite CJD,synaptic deposition of abnormal PrP was shown in 5 cases Conclusions (1)Of the 14 cases with CJD, homozygosity for methionine at condon 129 of the prion protein gene was shown in 12 cases,but there was distinct phenotypic variant (2)The frequence of methionine and valine of 129 allilic distribution for sCJD was similar to that in Japan,and different from that in Western cases There was no sCJD case with valine homozygous genotype at codon 129 in our study