【作者】 罗林紫；

【导师】 严新翔；

【作者基本信息】 中南大学 ， 神经病学， 2011， 硕士

【摘要】 背景与目的帕金森病(parkinson’s disease, PD)是发病率仅次于阿尔茨海默病的神经系统退行性疾病,以中脑黑质的多巴胺能神经元进行性丢失和残存细胞中出现含有α突触核蛋白的嗜酸性包涵体,即路易小体(Lewy bodies)为病理特征。多数PD患者为散发性和特发性,但也有少数帕金森综合征的发病是由基因突变引起。近年来,研究发现编码F-box protein 7蛋白的F-box only protein 7基因突变可导致PARK15。PARK15既往称为帕金森-锥体束综合征(Parkinsonian-pyramidal syndrome, PPS)或苍白球-锥体束病(Pallido-Pyramidal Disease, PPD),是指患者除帕金森样表现外尚合并有痉挛状态、腱反射亢进、病理征阳性等锥体束征表现。2008年,Shojaee(?)报道了一例合并有足内翻畸形的伊朗大家系,并利用500K SNP芯片进行全基因组连锁分析,在设定这个家系为常染色体隐性遗传背景的情况下,将突变区间定位至22q,并在该区间FBX07基因第7号外显子区发现一纯合错义突变(R378G)。2009年,Di Fonzo在一个意大利常染色体隐性遗传家系的2名患者中发现了FBXO7基因的纯合截短突变(R498X),并在另一个亦呈常染色体隐性遗传的荷兰家系中发现该基因由剪切位点突变和1号外显子区错义突变组成的复合杂合突变(IVS7+1G/T,T22M),并将这类疾病正式定名为PARK15。目前,世界上尚无对中国人群(包括中国大陆、中国台湾、新加坡等地)早发型FBX07基因突变的研究及分析。故而本研究旨在了解中国早发型帕金森综合征患者是否存在FBXO7基因突变及其特点。方法对135名早发型帕金森综合征患者及200名正常人的DNA进行FBXO7基因9个外显子的PCR扩增,将扩增产物直接测序后进行序列分析。结果本次实验PD患者组共发现10处多态,其中-274G→C和c.A155G为新发现的多态,另外8个为已报道的多态。经过X2检验发现,这10个多态等位基因频率及基因型频率在PD病例组与正常对照组相比没有统计学差异(P>0.05)。在多态连锁分析中,现lvs1+116C→T(rs8136485)和Ivsl+272T→G(rs8137714)呈完全连锁；二号外显子上的c.G345A (pM115I, rs11107)、Ivs6-75T→C (rs738982)和6号外显子上的c.C949T (pL317L, rs9726)也呈完全连锁(D’=1,r2=1)。结论FBXO7基因突变在中国早发型帕金森综合征患者中可能罕见；本次实验所发现的10个多态对于PARK15的发病没有影响,即：既不是致病因素,也不是保护性因素更多还原

【Abstract】 Background and objective Parkinson’s disease (PD), the second most common neurodegenerative disorder after Alzheimer’s disease, is pathologically characterized by the progressive loss of dopaminergic neurons in the substantia nigra of the midbrain, and the formation of alpha-synuclein-containing protein aggregates, termed Lewy bodies, in surviving neurons. PD is a sporadic, idiopathic disorder in most patients, but the identification of genetic mutations causing rare Mendelian forms of parkinsonism has provided novel clues for understanding of the disease pathogenesis. Recently, we characterized mutations in the F-box only protein 7 (FBXO7) gene, encoding the F-box protein 7 (FBXO7), as the cause of PARK15. PARK 15 used to be called Pallido-Pyramidal Disease (PPD) or Parkinsonian-Pyramidal Syndrome (PPS). It is associated with a series of symptoms that includes spasm state, hyperreflexia, and positive pyramidal signs besides the 3 classical PD symptoms (static tremor, bradykinesia, and rigidity). In 2008, Shojaee, etc, reported an Iranian pedigree, in which all affected individuals exhibited equinovarus deformity since childhood. The genome-wide linkage analysis on that pedigree with 500 K SNP arrays mapped the locus to chromosome 22, and a new disease-associated missense mutation (c.1132C→G) was found resulting in the nonconservative amino acid substitution of glycine for arginine at position 378(R378G) in the F-box protein 7.In 2009, Di Fonzo, etc, found an FBXO7 homozygous truncating mutation (Arg498Stop) in an Italian autosomal recessive early-onset parkinsonian pedigree, while compound heterozygous mutations (a splice-site IVS7+1G/T mutation and a missense Thr22Met mutation) presented in a Dutch family. Since then, gene FBXO7 was officially·designated as PARK15. Until now, no investigation of the mutation of FBXO7 in Chinese early-onset Parkinsonism patients has been done.Methods In this study, we executed polymerase chain reaction (PCR) combined with DNA direct sequencing on 135 Chinese early-onset Parkinsonism (including 23 unrelated probands with autosomal recessive early-onset Parkinsonism and 112 sporadic patients with early-onset Parkinson disease), and 200 normal Chinese people in order to screen the FBXO7 mutation.Results We found 10 sequence changes; of those,8 polymorphisms have been previously reported,2 others are newly discovered:-274G→C, C.A155G. No pathogenic mutation was found. All 10 base changes have been found in normal people. The difference between the frequency of those 10 polymorphisms in PD patients and the frequency in the control group was non-significant (P value> 0.05). We found that 2 polymorphisms are complete linkage with each other:Ivsl+116C→T (rs8136485) and Ivsl+272T→G (rs8137714). And 3 polymorphisms: c.G345A (pM115I, rs11107) in exon2, Ivs6-75T→C (rs738982) and c.C949T (pL317L, rs9726) in exon6 are complete linkage too. The D’=1 and the r2=1 when we analyzed them in this study.Conclusion FBXO7 mutations may be rare in Chinese early-onset Parkinsonism patients; those 10 polymorphisms found in this study have no effection in the expression of FBXO7 protein and the position of the protein either.更多还原