Rett Syndrome and long‐term disorder profile

Since the identification of mutations in MECP2 in females with clinical Rett syndrome, numerous efforts have been made to understand phenotype‐genotype relationships. Most of these studies were conducted by examining the type and localization of these mutations in the gene in relation to clinical severity. It seemed unsatisfactory, in view of the age range and variable severity, to look only at the type and localization of the mutation in MECP2 in trying to establish a phenotype/genotype relationship. Describing each RTT individual after a long term follow up and grouping females with the same disorder history and same MECP2 mutation is therefore appropriate. Complete clinical and molecular data were obtained on 103 females. The guidelines for reporting manifestations common in Rett syndrome were used in the evaluation of clinical severity. The individuals were grouped according to similar disorder profiles on long‐term follow up. In a cohort of 103 females clinically diagnosed with Rett syndrome, 91 had a detectable MECP2 mutation. 60% still sit and walk. Hand use is preserved or reduced in 44%. Speech has been lost in the majority (87%). Epilepsy was problematic in about 30%. Scoliosis, severe kyphosis or a combination of both was present in 27%, needing surgery in 13%. Description of the profile of the disorder and long‐term clinical history facilitated the grouping of females with the same MECP2 mutation and a similar history. This approach will contribute more to the understanding of the ongoing pathology in Rett syndrome relative to the specific character of the involved MECP2 mutation. Some examples of these disorder profiles will be discussed.