RESUMEN
PURPOSE: The purpose of this study was to identify the prevalence of mutations in the Myoclonin1/EFHC1 gene in Mexican patients with juvenile myoclonic epilepsy (JME). METHOD: We studied forty-one patients at the National Institute of Neurology and Neurosurgery in Mexico City and 100 healthy controls. DNA was extracted from the peripheral venous blood of all participants. The exons of EFHC1 were then amplified and sequenced. RESULTS: We found three new putative mutations, all of which were heterozygous missense mutations located in exon 3. The first identified mutation, 352C>T, produces a R118C change in the protein and cosegregated in the patient's affected father and brother. The second identified mutation, 544C>T, produces a R182L change in the protein and was found in the patient's asymptomatic father. The third identified mutation, 458>A, produces a R153Q change in the protein and was also found in the patient's father. These mutations were not found in controls. CONCLUSIONS: The frequency of Myoclonin1/EFHC1 mutations in our sample is 7.3%. Thus, we conclude that mutations in the Myoclonin1/EFHC1 gene are an important cause of JME in Mexican patients.