These resources include the best available evidence about the course of Rett syndrome and its management as well as practical information about family associations, specialist clinical centres and links to relevant websites.
Longitudinal bone mineral content and density in Rett syndrome and their contributing factors
Jefferson, A., Fyfe, S., Downs, J., Woodhead, H., Jacoby, P., & Leonard, H. (2015). Longitudinal bone mineral content and density in Rett syndrome and their contributing factors. Bone, 74, 191-198. Download snapshot, see article abstract.
Early studies have shown low bone mass and bone density in females with Rett syndrome. Sometimes children as young as three or four years old have low bone density, with even greater reductions in bone mass and density observed in older individuals, consequently impacting their risk of fracture. This study measured changes in bone density over time using dual energy x-ray absorptiometry (DEXA). Lean tissue or muscle mass (LTM) was also measured. We then investigated the effects of age, genotype, mobility, menstrual status and epilepsy on bone and muscle.
What we did
Measurements of bone status were taken at two time points: baseline and then three to four years later. Our cohort initially included 97 individuals from the Australian Rett Syndrome Database who were under 30 years of age. Of these individuals, 74 had a follow-up scan. Approximately one fifth of females were able to walk on their own at follow-up.
What we found
Overall, we found that bone area and lean tissue mass declined between individuals' baseline and follow-up scans. Levels of bone mineral density at the lumbar spine and the bone density and mineral content for the total body decreased over each year of study. Lean tissue mass volume, bone area for height and body mass index levels also decreased over each year.
Changes in bone mineral density were more positive in those who could walk unaided and in individuals who had already achieved menarche (first menstrual cycle) than those who had not. The lean tissue mass or volume of muscle tissue also decreased, possibly because of reduced mobility skills over time.
What it means
Declining bone density over time place individuals with Rett syndrome at a greater risk of fracture. Weight, height and muscle mass appear to impact bone formation. It is important for nutritional intake to be closely monitored and for families and clinicians to help develop a physical activity plan to promote bone health. The progression of puberty should be monitored in addition to performing bone assessments in order to track bone mass and density changes over time.
For further reports and findings, see our publications list.