CANDIDATE GENE ANALYSIS--INTEGRATIVE EFFORT TO CLONE NIEMANN-PICK TYPE C DISEASE

Niemann-Pick C型(NP-C)是一种常染色体隐性遗传的神经内脏病 以神经功能衰退为特征的障碍(渐进性认知 功能障碍、共济失调、肌张力障碍、吞咽困难、构音障碍、癫痫发作、猝倒 和痴呆)和胆固醇引起的肝脾肿大 脂肪沉积症。我们来自NINDS的合作者已经将NP-C本地化到18q11-q12， 更具体地说，在标记D18S44和D18S480之间的2 cM间隔内。 我们使用了一种综合的方法，涉及到基因组的利用 和用于NP-C细胞互补研究的cDNA克隆，以及 利用小鼠回交分析自然发生的小鼠模型 在快速减少候选者中补充重组研究 时间间隔。在人工酵母中成功组装该区域的重叠群 染色体(YACs)、(细菌人工染色体)BACs和粘粒； 序列分析；以及最近在候选基因中的突变搜索 结果鉴定出一个4.9kb的转录本，它编码一个 NP-C患者突变的142kD膜蛋白。的作用 这个基因，npc-1，在胆固醇运输和体内平衡中将是 用免疫组织化学、细胞生物学和建模技术检测 其他生物。

Niemann-Pick Type C (NP-C) is an autosomal-recessive, neurovisceral disorder that is marked by neurological decline (progressive cognitive impairment, ataxia, dystonia, dysphagia, dysarthria, seizures, cataplexy and dementia) and hepatosplenomegaly resulting from cholesterol lipidosis. Our collaborators from NINDS have localized NP-C to 18q11-q12, more specifically in a 2 cM interval between markers D18S44 and D18S480. We used an integrative approach that involved the utilization of genomic and cDNA clones for complementation studies of NP-C cells, as well as the use of mouse backcross analysis of naturally occurring murine models to supplement the recombinant studies in reducing rapidly the candidate interval. Succesful contig assembly of the region in yeast artificial chromosome (YACs), (bacterial artificial chromosome) BACs and cosmids; sequence analyses; and mutation searches in candidate genes recently resulted in the identification of a 4.9 kb transcript that encodes a membrane protein of 142 kD that is mutated in NP-C patients. The role of this gene, NPC-1, in cholesterol trafficking and homeostasis will be examined using immunohistochemistry, cellular biology and modeling in other organisms.