Bone mineral density and vitamin D receptor polymorphism in beta-thalassemia major.
Osteoporosis is the most prevalent bone complication in beta-thalassemic patients despite regular transfusions and iron chelation therapy. Although its etiology is multi-factorial, genetic factors play an important role in pathogenesis. These factors have not yet been clearly defined, however, osteoporosis may be related to vitamin D receptor gene BsmI polymorphism. In this study, BsmI vitamin D receptor gene polymorphism was analyzed using polymerase chain reaction and BsmI restriction fragment length polymorphism in 42 regularly treated-beta-thalassemic patients of different ages. Bone mineral density was measured by peripheral quantitative ultrasound at the heel of the foot. Serum levels of alkaline phosphatase, calcium, phosphorus, ferritin and 25-hydroxyvitamin D3 were determined. Patients were divided into two groups according to pubertal signs: group I (22 children), and group II (20 adolescents and adults). The Z-scores of bone mineral density in both groups were -1.32 +/- -0.9 and -2.30 +/- -1.02 respectively, with a significant difference between the two groups. The height standard deviation and 25-hydroxyvitamin D3 were significantly decreased in group II compared to group I. Moreover, significantly lower bone mineral density and height standard deviation were detected among patients with BB vitamin D receptor genotype. Therefore, this genotype may be considered as a risk factor for osteoporosis in beta-thalassemic patients.
El-Edel
Rawhia H
RH
Department of Clinical Pathology, Faculty of Medicine, Menoufiya University, Egypt. eledelr5000@yahoo.com
Ghonaim
Mabrouk M
MM
Abo-Salem
Osama M
OM
El-Nemr
Fathia M
FM
D000293:Adolescent; D000328:Adult; D000375:Aging / Q000235:genetics; D000469:Alkaline Phosphatase / Q000097:blood; D001827:Body Height / Q000235:genetics / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D002112:Calcifediol / Q000097:blood; D002118:Calcium / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D005293:Ferritins / Q000097:blood; D005838:Genotype; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000150:complications / Q000209:etiology; D010758:Phosphorus / Q000097:blood; D012150:Polymorphism, Restriction Fragment Length; D011627:Puberty / Q000097:blood / Q000235:genetics / Q000502:physiology; D018167:Receptors, Calcitriol / Q000235:genetics*; D012307:Risk Factors; D017086:beta-Thalassemia / Q000150:complications / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology
D018167:Receptors, Calcitriol; D010758:Phosphorus; D005293:Ferritins; D000469:Alkaline Phosphatase; D002112:Calcifediol; D002118:Calcium