title: Status of 25-hydroxyvitamin D deficiency and effect of vitamin D receptor gene polymorphisms on bone mineral density in thalassemia patients of North India.
abstract: BACKGROUND
  Bone disease comprising of low bone mineral density (BMD), bone pain, and fractures is a characteristic feature of thalassemia. Vitamin D receptors (VDRs - FokI, TaqI, and Bsml) polymorphisms are closely related to low BMD at the lumbar  spine and hips which can be used as a useful genetic marker in predicting bone disease in these patients.
  
  
  OBJECTIVE
  To find out the status of VDRs gene polymorphisms and its effect on osteoporosis in thalassemia patients of North Indian origin.
  
  
  METHODS
  BMD was measured in 40 beta-thalassemia major patients by dual-energy X-ray densitometry (DXA). Serum vitamin D levels were estimated by enzyme linked immunosorbant assay. VDR gene polymorphisms (FokI, TaqI, and BsmI) were analyzed by polymerase chain reaction restriction  fragment length polymorphism (PCR-RFLP) method.
  
  
  RESULTS
  About 80.6% cases were found to be vitamin D deficient. Z score of BMD of lumbar spine and hips were -2.31 ± 1.18 and -2.09 ± 0.89. Osteoporotic lumbar spine was  observed in 42.5% cases of thalassemia. A positive correlation of vitamin D level was found with Z score of BMD of lumbar spine (r = 0.398, P value = 0.027). Polymorphisms of FokI and BsmI were found significantly correlated with BMD of  lumbar spine. However, no association of BMD was observed with TaqI polymorphism.
  
  
  CONCLUSIONS
  The present study showed a high prevalence of low BMD in thalassemia, suggesting that they should be targeted for DXA screening and osteoporosis prevention before permanent  end organ bone damage occurs. The VDR genotyping can be used as additional test in individuals who are susceptible to osteoporosis so that early preventive measurements can be taken.
authors.affiliation: Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
authors.forename: Kritanjali
authors.initials: K
authors.lastname: Singh
authors.forename: Ravindra
authors.initials: R
authors.lastname: Kumar
authors.forename: Anju
authors.initials: A
authors.lastname: Shukla
authors.forename: Shubha R
authors.initials: SR
authors.lastname: Phadke
authors.forename: Sarita
authors.initials: S
authors.lastname: Agarwal
mesh_terms: D000293:Adolescent; D000328:Adult; D015519:Bone Density; D002648:Child; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D010024:Osteoporosis / Q000150:complications / Q000453:epidemiology / Q000235:genetics / Q000517:prevention & control; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D018167:Receptors, Calcitriol / Q000235:genetics*; D013789:Thalassemia / Q000150:complications / Q000453:epidemiology* / Q000235:genetics*; D014807:Vitamin D / Q000031:analogs & derivatives*; D014808:Vitamin D Deficiency / Q000150:complications / Q000453:epidemiology* / Q000235:genetics* / Q000517:prevention & control
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D