C9orf72（C9orf72-SMCR8 complex subunit），癌症关联基因，基因ID：203228，该基因编码的蛋白质在内质体运输的调控中起着重要作用，并与参与自噬和内吞转运的rab蛋白相互作用。在该基因转录本的5'外显子之间的内含子序列中，GGGGCC重复序列从2-22拷贝扩展到700-1600拷贝与9P连锁的肌萎缩侧索硬化（ALS）和额颞叶痴呆（FTD）有关（PMID:21944778，21944779）。研究表明，在ftd-als患者中，六核苷酸的扩增可导致含有pre-mrna的重复序列的选择性稳定，以及不溶性二肽重复序列蛋白聚集体的积累（pmid:23393093）。选择性剪接导致编码不同亚型的多个转录变体[由RefSeq提供，2016年7月]The protein encoded by this gene plays an important role in the regulation of endosomal trafficking， and has been shown to interact with Rab proteins that are involved in autophagy and endocytic transport. Expansion of a GGGGCC repeat from 2-22 copies to 700-1600 copies in the intronic sequence between alternate 5' exons in transcripts from this gene is associated with 9p-linked ALS (amyotrophic lateral sclerosis) and FTD (frontotemporal dementia) (PMID: 21944778， 21944779). Studies suggest that hexanucleotide expansions could result in the selective stabilization of repeat-containing pre-mRNA， and the a。