Genetic and clinical variations in a Norwegian sample diagnosed with Rett syndrome

Abstract

Rett syndrome (RTT) is a neurodevelopmental disorder that almost exclusively affects females. Epilepsy is a major clinical feature, but its long-term course in RTT has not been sufficiently explored. This study addresses the development of the epilepsy in adults with RTT. Methods: Available females diagnosed with RTT in Norway were asked to participate. Parents/caregivers were interviewed, the girls/women were examined and their medical records reviewed. Participants were categorized according to age, epilepsy, seizure patterns and mutation severity groups. RTT severity was assessed (epilepsy score excluded). Results: 70 females with classic RTT were included. A presumed pathogenic mutation in MECP2 was found in 96%. The presence of active epilepsy (seizures last five years) was similar in all age groups above the age of ten: 11 (65%) in adolescents (11-20 years), 9 (60%) in young adults (21-30 years) and 14 (67%) in participants above 30 years of age. Tonic-clonic seizures within the last year were present in 55, 67 and 64%, and ≥ weekly seizures occurred in 27, 45 and 50% in the respective age groups. Among participants with active epilepsy, 69% had unremitting seizures, whereas 31% had experienced remissions for more than six months during the last five years. In the oldest group (> 30 years), only 19% had obtained seizure control for > 5 years, and 14% had never experienced seizures. Seizure activity correlated with RTT severity score, whereas the relationship to mutation type remained ambiguous. Conclusion: Epilepsy continues to be a major concern in adults with RTT. Two thirds of women above 30 years of age remained with active epilepsy and 50% of them had seizures at least weekly.