Clinical Guidelines for Management of Bone Health in Rett Syndrome Based on Expert Consensus and Available Evidence.

OBJECTIVES: We developed clinical guidelines for the management of bone health in Rett syndrome through evidence review and the consensus of an expert panel of clinicians. METHODS: An initial guidelines draft was created which included statements based upon literature review and 11 open-ended questions where literature was lacking. The international expert panel reviewed the draft online using a 2-stage Delphi process to reach consensus agreement. Items describe the clinical assessment of bone health, bone mineral density assessment and technique, and pharmacological and non-pharmacological interventions. RESULTS: Agreement was reached on 39 statements which were formulated from 41 statements and 11 questions. When assessing bone health in Rett syndrome a comprehensive assessment of fracture history, mutation type, prescribed medication, pubertal development, mobility level, dietary intake and biochemical bone markers is recommended. A baseline densitometry assessment should be performed with accommodations made for size, with the frequency of surveillance determined according to individual risk. Lateral spine x-rays are also suggested. Increasing physical activity and initiating calcium and vitamin D supplementation when low are the first approaches to optimizing bone health in Rett syndrome. If individuals with Rett syndrome meet the ISCD criterion for osteoporosis in children, the use of bisphosphonates is recommended. CONCLUSION: A clinically significant history of fracture in combination with low bone densitometry findings is necessary for a diagnosis of osteoporosis. These evidence and consensus-based guidelines have the potential to improve bone health in those with Rett syndrome, reduce the frequency of fractures, and stimulate further research that aims to ameliorate the impacts of this serious comorbidity.

The trajectories of sleep disturbances in Rett syndrome.

Rett syndrome is a rare neurodevelopmental disorder usually affecting females, and is associated with a mutation in the MECP2 gene. Sleep problems occur commonly and we investigated the trajectories and influences of age, mutation and treatments. Data were collected at six time points over 12 years from 320 families registered with the Australian Rett Syndrome Database. Regression analysis was used to investigate relationships between sleep disturbances, age, mutation type and use of treatment, and latent class growth analysis was performed to identify sleep problem phenotypes and model the effect of mutation type. The age range of subjects was 2.0-35.8 years. The study showed that sleep problems occurred in more than 80% of individuals and the prevalence decreased with age. Night laughing and night screaming occurred in 77 and 49%, respectively, when younger. Those with a large deletion had a higher prevalence of night laughing, which often occurred frequently. Treatment was associated with a 1.7% reduction in risk of further sleep problems. High and low baseline prevalence groups were identified. Approximately three-quarters of girls and women with sleep disturbances were in the high baseline group and problems persisted into adulthood. Conversely, 57% with night laughing and 42% with night screaming in the high baseline group exhibited mild improvement over time. Mutation type was not found to be a significant predictor of group membership. In conclusion, the evolution of sleep problems differed between subgroups of girls and women with Rett syndrome, in part explained by age and genotype. Treatment was not associated with improvement in sleep problems.

Dietary L-tyrosine supplementation in nemaline myopathy.

Nemaline myopathy is defined by the presence of nemaline bodies, or rods, on muscle biopsy. Facial and bulbar weakness in nemaline myopathy cause chewing and swallowing difficulties, recurrent aspiration, and poor control of oral secretions. This article discusses 5 patients (4 infants and 1 adolescent) with nemaline myopathy who received dietary supplementation with L-tyrosine (250 to 3000 mg/day). All 4 infants were reported to have an initial decrease in sialorrhoea and an increase in energy levels. The adolescent showed improved strength and exercise tolerance. No adverse effects of treatment were observed. Dietary tyrosine supplementation may improve bulbar function, activity levels, and exercise tolerance in nemaline myopathy.