Frecuencia del síndrome de X-Frágil en la consulta de genética del Hospital Nacional de NiñosWe discussed the importance of the X-Fragile citogenetic studies in the mental retardation that affects mainly men, is hereditary and in our media presents a mental discapacity syndrome. We studied 150 children with mental retardation, since January 1995 and July 1997. They were refered to our laboratory for X-Fragile analysis. We got 10, 6% of positives: 8,6% boys and 2% girls.