Vitamin D deficiency in serbian patients with rett syndrome

Abstract

Introduction: Rett syndrome (RTT) is a severe neurodevelopmental disorder. Bone manifestations of RTT include osteopenia and fractures. Studies addressing serum vitaminDlevels in patients with RTT are scarce. Goals: The goals of this study were (1) to determine the prevalence of vitamin D deficiency in patients with RTT, (2) to compare serum vitaminDlevels between patients with RTT and those with other neurological diseases, and (3) to explore the correlation between demographic and clinical characteristics of patients with RTT and vitamin D levels. Methods: Demographic and clinical characteristics included age, body mass index Z-score, mutation status, clinical severity score, presence of epilepsy, number of antiepileptic drugs, history of fractures, scoliosis, and ambulation ability. Laboratory parameters included serum 25-hydroxyvitamin D [25(OH)D], PTH, calcium, and alkaline phosphatase. Results: The study included 35 patients with RTT and 35 age-matched females with other neurological diseases. The median serum 25(OH)D concentration in the RTT group was 26.25 nmol/L, with values <75 nmol/L in all participants. Severe deficiency (<25 nmol/L) was detected in 17 of 35 (48.6%) patients. The median 25(OH)D concentration was significantly lower in patients with RTT than in control subjects. The risk for fracture by 12 years of age in patients with RTT was 35.3%. An inverse correlation of the 25(OH)D level to age and PTH level was detected. Patients receiving antiepileptic polytherapy had a 3.3 times greater chance for severe vitamin D deficiency than patients receiving monotherapy. Conclusion: The prevalence of vitamin D deficiency in patients with RTT is higher than that in patients with other neurological diseases. The high risk for vitamin D deficiency should be accounted for in the strategy of antiepileptic treatment in RTT, especially when polytherapy is considered. Copyright © 2013 by The Endocrine Society.