[Fragile X syndrome and epilepsy]. / Síndrome X frágil y epilepsia.

Fragile X syndrome is the most frequent cause of genetically related mental retardation. Epilepsy, occurring in 20 to 40% of cases, is considered a minor sign. Age- and sex-dependent EEG patterns analogous to partial idiopathic epilepsy with rolandic paroxysms have been described. We analyze the clinical and electrical manifestations in a series of 10 patients between 4 and 60 years old; 3 suffered partial seizures developing into generalized seizures and 2 asymptomatic patients had EEG signs. In the remaining patients only slow background activity was observed. The EEG pattern and epileptic seizures were seen only in males. We believe that the association of sharp waves preceding rolandic paroxysm is a differential trait suggesting a structural alteration.