GENETIC MARKERS OF LOW BONE MINERAL DENSITY IN PATIENTS WITH CYSTIC FIBROSIS

Abstract

ABSTRACT: Introduction: failure to maintain bone mass density is a major problem in patients with cystic fibrosis (CF). CF is due to mutations in the CFTR gene and other genes may contribute to modifying the disease. Genetic and environmental factors may play a role in determining the variability of bone mass. Aim of the study: to analyse the association between polymorphic variants of genes considered to be risk factors of bone metabolism disturbances and decreased bone mineral density (BMD) in children and adults with CF in R. Macedonia. Materials and methods: the study included 80 clinically stable CF patients (age range 5-36y), who regularly attended the CF center at the Pediatric Clinic in Skopje, Macedonia. Three candidate genes likely associated with BMD variability were studied: the vitamin D receptor (VDR) gene, the estrogen receptor alpha (ESR1) and the type I alpha I collagen (COLIA1) gene. A complete bone and CF evaluation was obtained for all patients: 55 had normal BMD (group 1), 17 were osteopenic (group 2) and 8 were osteoporotic (group 3). Results: Low bone mineral density (Z score < -1SD) was found in 31.25% patients and in 10% of them BMD was below -2SD. Patients with low BMD had worse BMI, FEV1 and more severe symptoms of CF. No significant correlation was found between COLIA1 and VDR polymorphisms and BMD. Conclusion: There was no evidence that the genes under study may modulate bone phenotype in CF.