this was later confirmed in Italian, French, British, Russian and Icelandic populations. However, it appears to be less common in Chinese, and is absent in Japanese but no such study has been conducted in the homogeneous population from Northern India. This study was therefore conducted to determine the prevalence of CFH polymorphism and to test whether differences in levels of serum CFH exist between Indian patients with AMD and healthy controls. We report significantly lower serum CFH levels in AMD patients as compared to controls and Y402H variant of CFH to be associated with AMD in this population. Homozygous CC and heterozygous TC genotypes were more frequent among AMD patients than controls. Moreover, the CC and TC genotypes conferred OR for AMD of 16.5 and 12.6, respectively. CFH is involved in the inflammatory response of the innate immune system. Low levels of CFH in North Indian population is consistent with other reports. Dhillon et al showed that the prevalence of factor H autoantibodies decreased in AMD patients as compared with normal controls. Some investigators have shown that reduced serum CFH is associated with obesity, hypertension and Microcystin-LR smoking which are known risk factors for AMD. In a recent study, Silva et al observed significant differences in the plasma levels of the alternative pathway proteins i.e. Factor D and Factor I between the AMD patients and control. They showed significantly lower FD plasma levels and higher FI levels in AMD patients and also identified a significant decrease in CFH plasma levels in AMD females patients in relation to normal females. Several studies have previously examined the role of CFH Y402H polymorphism in the AMD subtypes such as geographic atrophy or choroidal neovascularization. The weakly regulated complement cascade, due to CFH polymorphism, might enhance cellular damage, ultimately leading to atrophy or neovascular response. In the patients investigated the Y402H polymorphism was not predictive for either of these AMD GSK137647A phenotypes. This supports the concept that it could be involved in both dry and wet AMD variants. It is pertinent to note that conflicting results exist where such associations have been investigated wherein some groups have suggested that neovascular AMD to be at a higher risk of this genotype variant while others noting that atrophic AMD represents a higher risk of this polymorphism, however, there are many others who have reported it to bear no variation with AMD phenoty
