ESPE Abstracts

Background: Beta thalassemia major (BTM) is considered a major health problem. Despite optimal conventional treatment, bone disease comprising of low bone mineral density (BMD), bone pain, and fractures is still a characteristic feature of thalassemia. The etiology of bone disease in thalassemia is multifactorial. vitamin D receptor (VDR) mediates the action of 1,25(OH)2D, The VDR genetic variations may be responsible for modifying the activity of VDR protein.

Objective: To study the effect of Vitamin D status and Vitamin D receptor genetic variation in bone mineral density in Egyptian patients with BTM.

Subjects and Methods: The Study included eighty children with BTM and eighty age & sex- matched controls group. Patients with any renal or hepatic impairment, hyperparathyroidism or using medications affecting bone mineral metabolism (as glucocorticoids or anticonvulsant drugs) were excluded.serum calcium, phosphorus and ALP and 25 vitamin D were measured, VDR genotyping regarding BsmI, TaqI, FokI single nucleotide polymorphisms was carried out. Every patient underwent dual-energy X-ray absorption (DEXA) scan of the lumbar spine.

Results: There was a significantly lower 25 vitamin D with bb, Ff and ff vitamine D receptor genotype. The Z score of BMD of the lumbar spine was significantly lower with Bb, bb, Ff and ff vitamine D receptor genotype. No significant association was observed in 25 vitamin D and the Z score of BMD with TaqI polymorphism.

Conclusion: The VDR genotyping can be used as an additional test in children who are vulnerable to osteoporosis so that early preventive can be taken.