Frequency of the fragile X syndrome in Chinese mentally retarded populations is similar to that in Caucasians

• Published in: American journal of medical genetics 1999-05, Vol.84 (3), p.191-194
• Main Authors: Zhong, Nan, Ju, Weina, Xu, Weimin, Ye, Lingling, Shen, Yan, Wu, Guangyun, Chen, Shi-han, Jin, Runming, Hu, Xiao-feng, Yang, Aide, Liu, Xixian, Poon, Priscilla, Pang, Calvin, Zheng, Yu, Song, Li, Zhao, Pei, Fu, Bojing, Gu, Hongjuan, Brown, W. Ted
• Format: Article
• Language: English
• Subjects: Alleles; China - epidemiology; Chinese; European Continental Ancestry Group; Female; founder chromosomes; Founder Effect; fragile X syndrome; Fragile X Syndrome - epidemiology; Fragile X Syndrome - genetics; Genetic Testing; Haplotypes; Humans; Intellectual Disability - epidemiology; Intellectual Disability - genetics; Male; microsatellites; molecular screening; X Chromosome - genetics
• ISSN: 0148-7299; 1096-8628
• DOI: 10.1002/(SICI)1096-8628(19990528)84:3<191::AID-AJMG3>3.0.CO;2-8

Fragile X syndrome is recognized as the most common inherited cause of mental retardation in western countries. The prevalence of the fragile X syndrome in Asian populations is uncertain. We report a multi‐institutional collaborative study of molecular screening for the fragile X syndrome from 1,127 Chinese mentally retarded (MR) individuals. We found that 2.8% of the Chinese MR population screened by DNA analysis had the fragile X full mutation. Our screening indicated that the fragile X syndrome prevalence was very close to that of Caucasian subjects. In addition, we found that 62.5% of fragile X chromosomes had a single haplotype for DXS548‐FRAXAC1 (21‐18 repeats) which was present in only 9.7% of controls. This unique distribution of microsatellite markers flanking the FMR1 CGG repeats suggests that the fragile X syndrome in Chinese populations, as in the Caucasian, may also be derived from founder chromosomes. Am. J. Med. Genet. 84:191–194, 1999. © 1999 Wiley‐Liss, Inc.