中国Rett综合征患儿突变基因的亲源分析

Objective To identify the parental origin of methyl-CpG-binding protein 2 (MECP2)gene mutations in Chinese patients with Rett syndrome. Methods Single nucleotide polymorphisms (SNPs) in intron 3 of the MECP2 gene were analyzed by PCR and sequencing in 115 patients with Rett syndrome.Then sequencing of the SNP region was performed for the fathers of the patients who had at least one SNP,to determine which allele was from the father. Then allele-specific PCR was performed and the products were sequenced to see whether the allele from father or mother harbored the mutation. Results Seventy-six of the 115 patients had at least one SNP. Three hot SNPs were found in these patients. They were: IVS3+22C＞G, IVS3+266C＞T and IVS3+683C＞T. Among the 76 cases, 73 had a paternal origin of MECP2 mutations, and the other 3 had a maternal origin. There were multiple types of MECP2 mutation of the paternal origin, including 4 frame shift, 2 deletion and 67 point (56 C＞T, 6 C＞G, 2 A＞G, 2 G＞T and 1 A＞T) mutations. The mutation types of the 3 ptients with maternal origin included 2 frame shift and 1 point (C＞T) mutation. Conclusion In Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.

Analysis of the parental origin of MECP2 mutations in patients with Rett syndrome