Down syndrome (DS) is the most common genetic cause of intellectual disability, resulting from lack of disjunction of sister chromatids of human chromosome 21 or not partial disjunction of chromosome 21 (Hsa21), usually during maternal meiosis. The expression of genes in chromosome 21 is very complex and many other genes in other chromosomes can play a role in DS. The protein encoded by the Cerebellar degeneration-related autoantigen 1 (CDR1) gene has been identified in patients with paraneoplastic cerebellar degeneration. Transcriptome studies show CDR1 expression in tumor cell lines and leukocytes of normal subjects and patients with Alzheimer's disease. We investigated CDR1 expression in cultured fibroblasts of DS patients compared with normal subjects. The study of CDR1 mRNA was performed with qRT-PCR. Immunofluorescence and Western blot were used for the analysis of the CDR1 protein. Our data show that both CDR1 mRNA and protein are expressed in human fibroblasts and that the CDR1 gene is down-regulated in DS fibroblasts compared to controls. These data suggest a role for CDR1 in DS phenotype.

唐氏综合症（DS）是智力障碍的最常见遗传原因，通常是在母亲减数分裂期间，由于人类21号染色体的姐妹染色单体缺乏分离或21号染色体（Hsa21）没有部分分离引起的。基因在21号染色体中的表达非常复杂，其他染色体中的许多其他基因也可以在DS中起作用。在副肿瘤性小脑变性患者中已鉴定出由小脑变性相关自身抗原1（CDR1）基因编码的蛋白质。转录组研究显示CDR1在正常受试者和阿尔茨海默氏病患者的肿瘤细胞系和白细胞中表达。我们调查了CDR1与正常人相比，DS患者培养的成纤维细胞中的表达水平。CDR1 mRNA的研究使用qRT-PCR进行。免疫荧光和蛋白质印迹用于分析CDR1蛋白。我们的数据显示，与对照组相比，CDR1 mRNA和蛋白质均在人成纤维细胞中表达，并且CDR1基因在DS成纤维细胞中被下调。这些数据表明CDR1在DS表型中的作用。