Next-Generation Sequencing Reveals One Novel Missense Mutation in COL1A2 Gene in an Iranian Family with Osteogenesis imperfecta

BAckground: Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous disorder characterized by bone loss and bone fragility. The aim of this study was to investigate the variants of three genes involved in the pathogenesis of OI. Methods: Molecular genetic analyses were performed for COL1A1, COL1A2, and CRTAP genes in an Iranian family with OI. The DNA samples were analyzed by next-generation sequencing (NGS) gene panel and Sanger sequencing. Results: Five different variants were identified in COL1A1 and COL1A2, including two variants in COL1A1 and three variants in COL1A2. Among the five causative COL1A1 and COL1A2 variants, one novel variants, c.1081 G>A, was found in COL1A2, which was identified in two siblings. Conclusion: Our finding extends the variant spectrum of the COL1A2 gene and has important implications for genetic counseling of families. The NGS is a powerful molecular diagnostic strategy for OI, a heterogeneous disorder.

Molecular Aspects of Bone Resorption in ß-Thalassemia Major.

ß-thalassemia is the most common single gene disorder worldwide, in which hemoglobin ß-chain production is decreased. Today, the life expectancy of thalassemic patients is increased because of a variety of treatment methods; however treatment related complications have also increased. The most common side effect is osteoporosis, which usually occurs in early adulthood as a consequence of increased bone resorption. Increased bone resorption mainly results from factors such as delayed puberty, diabetes mellitus, hypothyroidism, ineffective hematopoiesis as well as hyperplasia of the bone marrow, parathyroid gland dysfunction, toxic effect of iron on osteoblasts, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) deficiency. These factors disrupt the balance between osteoblasts and osteoclasts by interfering with various molecular mechanisms and result in decreased bone density. Given the high prevalence of osteopenia and osteoporosis in thalassemic patients and complexity of their development process, the goal of this review is to evaluate the molecular aspects involved in osteopenia and osteoporosis in thalassemic patients, which may be useful for therapeutic purposes.