Increased boneresorption mainly results from factors such as delayed puberty, diabetes mellitus, hypothyroidism,ineffective hematopoiesis as well as hyperplasia of the bone marrow, parathyroidgland dysfunction, toxic effect of iron on osteoblasts, growth hormone (GH) andinsulin-like growth factor-1 (IGF-1) deficiency. The gene discussed is IGF1; the disease is hypothyroidism.