Although the severity of symptoms and the age at which they manifest themselves varies, Rett syndrome has just one cause: mutations in a single gene called MeCP2.

• 虽然这种疾病的严重程度和发作时间因人而异，但雷特氏综合征只有一个起因，那就是，一个叫做MeCP2的单基因发生了突变。