Fragile X founder effect and distribution of CGG repeats among the mentally retarded population of Andalusia, South Spain

• Autor(a) principal: Diego,Yolanda de
• Data de Publicação: 2002
• Outros Autores: Hmadcha,Abdelkrim, Moron,Francisco, Lucas,Miguel, Carrasco,Mercedes, Pintado,Elizabeth
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Genetics and Molecular Biology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000100002
• topic: mental retardation; fragile X syndrome; CGG repeats; genetic screening

Fragile X syndrome is the most common inherited form of mental retardation. We investigated the prevalence of the Fragile X syndrome in the population with mental retardation of unknown etiology in Andalusia, South Spain. We analyzed 322 unrelated patients (280 males and 42 females), and found a fragile X syndrome frequency of 6.5%. Among the non-fragile X chromosomes, the 29 CGG repeat was the most common allele. At the linked microsatellite DXS548 locus, we found a new allele which we called "allele 10" (17 CA). Similar to other south European populations, allele 2 (25 CA) at the DXS548 locus and the fragile X allele were in linkage disequilibrium supporting the idea of a common founder chromosome predisposing to the CGG expansion.