Distribution ofFMR-1 and associated microsatellite alleles in a normal Chinese population

✍ Scribed by Zhong, Nan ;Liu, Xixian ;Gou, Shen ;Houck, George E. ;Li, Shuyun ;Dobkin, Carl ;Brown, W. Ted

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 538 KB
• Volume: 51
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320510423

✦ Synopsis

Republic of China

The CGG repeat size distribution of the fragile X mental retardation gene (FMR-1) was studied in a population of normal Chinese X chromosomes along with that of two proximal microsatellite polymorphic markers: FRAXACl and DXS548. The most common CGG repeat allele was 29 (47.2%) with 30 being second most common (26%). This distribution was different from that seen in Caucasian controls, where the most common allele was 30 repeats. Other differences with Caucasian controls included a secondary modal peak at 36 repeats and the absence of peaks at 20 or 23 repeats. There were only two FRAXACl and five DXS548 alleles found in the Chinese sample. A striking linkage disequilibrium of FMR-1 alleles with FRAXACl alleles was observed, in that 90% of the 29 CGG repeat alleles but only 41% of the 30 CGG repeat alleles had the FRAXACl 152 bp allele (18 AC repeats). This disequilibrium suggests that slippage between the closely spaced normal CGG repeat alleles, 29 and 30, and between 152 and 154 FRAXACl alleles is very rare. This study lays the groundwork for an understanding of founder chromosome effects in comparing Asian and Caucasian populations.