Epilepsy in Rett syndrome: association between phenotype and genotype, and implications for practice.

Purpose: To investigate the association between genotype (methyl-CpG-binding protein 2 (MECP2 gene mutation)) and epileptic seizure phenotype in Rett syndrome.

Methods: We used the British Isles Rett syndrome survey to identify 137 subjects with one of the nine most frequent MECP2 gene mutations and invited their parents or carers to participate in a postal questionnaire and telephone interview. The questionnaire recorded information about epileptic seizure types, non-epileptic vacant spells and treatments.