自閉癥是一種具有高度遺傳性的神經(jīng)發(fā)育疾病,，然而迄今所發(fā)現(xiàn)的特定易感基因非常少。現(xiàn)在，在一組1,031個(gè)多元化自閉癥家庭中利用50萬個(gè)全基因組SNP（單核苷酸多態(tài)性）所進(jìn)行的一次全基因組掃描，顯示了與自閉癥相關(guān)的重要關(guān)聯(lián),。所發(fā)現(xiàn)的關(guān)聯(lián)區(qū)域?yàn)楹币娮儺惡Y選提供了目標(biāo)，同時(shí)研究人員還在染色體5p15上的SEMA5A 和TAS2R1之間發(fā)現(xiàn)了一個(gè)新的關(guān)聯(lián),。SEMA5A的表達(dá)被發(fā)現(xiàn)在自閉癥患者腦中減少，從而進(jìn)一步證實(shí)它是一個(gè)自閉癥易感基因,。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 461, 802-808 (8 October 2009) | doi:10.1038/nature08490
A genome-wide linkage and association scan reveals novel loci for autism
Lauren A. Weiss1,2,77,75, Dan E. Arking3,77 & The Gene Discovery Project of Johns Hopkins & the Autism Consortium
Although autism is a highly heritable neurodevelopmental disorder, attempts to identify specific susceptibility genes have thus far met with limited success1. Genome-wide association studies using half a million or more markers, particularly those with very large sample sizes achieved through meta-analysis, have shown great success in mapping genes for other complex genetic traits. Consequently, we initiated a linkage and association mapping study using half a million genome-wide single nucleotide polymorphisms (SNPs) in a common set of 1,031 multiplex autism families (1,553 affected offspring). We identified regions of suggestive and significant linkage on chromosomes 6q27 and 20p13, respectively. Initial analysis did not yield genome-wide significant associations; however, genotyping of top hits in additional families revealed an SNP on chromosome 5p15 (between SEMA5A and TAS2R1) that was significantly associated with autism (P = 2*10-7). We also demonstrated that expression of SEMA5A is reduced in brains from autistic patients, further implicating SEMA5A as an autism susceptibility gene. The linkage regions reported here provide targets for rare variation screening whereas the discovery of a single novel association demonstrates the action of common variants.
