H6PD and obesity due to melanocortin 4 receptor deficiency: Martínez-García and colleagues studied the association of rs6688832 and rs34603401 polymorphisms in the H6PD gene with obesity and polycystic ovary syndrome (PCOS) on 237 cases and 135 controls and they found that the variants in the H6PD gene were associated with obesity and PCOS (Martínez-García et al., 2012).