Endocrine Abstracts

Introduction: Severe generalised recessive dystrophic epidermolysis bullosa (RDEB) is a rare disorder resulting from loss of function mutations in the type VII collagen gene (COL7A1). Although RDEB is characterised by severe trauma induced skin blistering and erosions, it is a multisystem disorder with low bone mass as one of the many complications.

Objectives: We sought to describe the prevalence of low bone mass, vertebral fractures and scoliosis in children with RDEB between the ages of 7–8 years and compare this to children of the ages 15–18 years.

Method: This was a retrospective, observational study of 22 patients aged 7–8 years and 15 patients aged 15–18 years. Primary outcome measures were BMD Z scores, areal BMD (aBMD), presence of vertebral fractures and scoliosis.

Results: The mean lumbar spine aBMD±S.D. of children aged 7.7±0.5 years Z score was −1.8±1.2 and aBMD 0.550.1 g/cm². Twenty-seven percent of the children had vertebral compression fractures and 5% had scoliosis.

This compared with mean lumbar spine aBMD of children aged 16.5±1.2 years Z score of −4.4±1.2 and aBMD of 0.68±0.2 g/cm². Thirty-eight percent of these children had vertebral compression fractures and 33% had scoliosis.

Whilst there was a significant increase in the aBMD (P<0.006) in the older cohort, there was a highly significant decrease in BMD Z score (P<0.0001) with over a third of children aged 15–18 years having vertebral compression fractures and scoliosis.

Conclusions: Children with RDEB have low BMD Z scores in childhood which declines with age. Despite early preventative interventions such as optimising nutrition, vitamin D supplementation and physiotherapy, there is still an increase in complications including vertebral compressions and scoliosis. The cause of low bone mass is multifactorial in nature but we are beginning to understand the major role of chronic inflammation in fuelling this process.