“…The G and C alleles respectively have been associated with higher gene expression (Alonso et al, 2011), and increased serum estrogen levels Sowers et al, 2006), although not consistently (Malacara et al, 2004;Yaffe et al, 2009). In a similar manner, one or both alleles have also been associated with more favourable estrogen-dependent outcomes such as higher bone mass density and lower fractures (Ioannidis et al, 2002)), and a decreased risk of cognitive impairment (Yaffe et al, 2002), Alzheimer's disease (Monastero et al, 2006), phobia (Ryan et al, 2011b), general anxiety (Tiemeier et al, 2005) and cardiovascular disease . On the other hand, other studies have also reported both null (den Heijer et al, 2004;Koch et al, 2005;Silvestri et al, 2006) and reverse findings (Brandi et al, 1999;Shearman et al, 2003).…”