Ultimos avances en el síndrome de fragilidad del cromosoma X / Last advances in fragile X chromosome syndrome

The Fragile X syndrome is one of the most frequent forms of mental retardation. The responsible mutation is an unstable repetitive sequence. Since the mutation's discovery, the knowledge about the gene, its protein, function, expression, laboratory detection, phenotype-genotype relationship and risk of expansion, has enormously increased. This work pretends to review the recent advances in this syndrome in all its aspects.