Asghar et al. [5] investigated the possible association between endometriosis and the TNF-α gene promoter polymorphism rs1799964, rs1799724, rs1800629, rs361525 and rs1800630 in a Japanese population. No significant differences in frequencies between the crude endometriosis cases and controls were reported for the above-studied polymorphism. Division of endometriosis group in a subgroup of women with stage IV disease only, the frequency of rs1799964 C allele, was significantly lower in this subgroup than controls. Therefore, the study suggested that the TNF-α rs1799964 polymorphism might be associated with susceptibility to endometriosis.

During ageing, there is 2- to 4-fold increase in plasma levels of inflammatory mediators such signaling pathway as TNF-α, IL-6, interleukin 1 receptor antagonist (IL-1Ra), soluble TNF-α

receptor (sTNFR), acute-phase proteins, such as C-reactive protein (CRP), and neutrophils has been reported. This low-grade inflammation may play an important role in age-related diseases such as Alzheimer’s disease, atherosclerosis, type 2 diabetes, osteoporosis, as well as sarcopenia. TNF-α played role in many age-related inflammatory changes, whereas other cytokines like IL-6, IL-1Ra, sTNFR, as well as acute-phase proteins (APPs) like CRP, reflect responses to upregulated local or generalized TNF-α activity [141]. The authors have detected five TNF promoter SNPs, including rs1799964, rs1799724, rs1800629, rs361525 and rs1800630. LY2606368 The rs1799964 and rs1800630, putative high-expression alleles individually or in the haplotype rs1799964 C- rs1800630 A- rs1799724

C- rs1800629 G- rs361525 G, were associated with lower muscle mass in men. Carriers of rs1799964 C, compared with non-carriers, exhibited lower arm muscle mass also tending to be lower. Similarly, rs1800630 A allele carriers (linked with rs1799964), Cyclin-dependent kinase 3 compared with non-carriers, exhibited lower arm muscle mass. Carriers of the haplotype rs1799964 C- rs1800630 A- rs1799724 C- rs1800629 G- rs361525 G, compared with non-carriers, exhibited lower arm muscle mass and trunk muscle mass. Interleukin (IL)-6, a cytokine, plays an important role in the differentiation and activation of osteoclasts and might be involved in osteoblast stimulation in Paget’s disease of bone (PDB). Corral-Gudinol et al. [142] investigated the association of IL-6, IL-8 and TNFα (rs1800629 and rs361525) polymorphism in patients with PDB and healthy controls in Spanish population. No significant association between genotype and allele distribution of any of the cytokines polymorphism and PDB was observed. The study concluded that Paget’s disease of bone is not associated with polymorphism in interleukin-6, interleukin-8 and tumour necrosis factor-alpha genes. Genetic factors have role in proliferative vitreoretinopathy (PVR).