Of note, there were several genes (AFF3, CRHR1, FERMT2, GRK4, LINC01104, LRFN2, MADD, MAD1L1, and ZNF652) identified in the meta-analyses were associated with AD or had a pleiotropic relationship with AD and its risk factors such as obesity-related traits (Comuzzie et al., 2012), cognitive performance (Lee et al., 2018), EA (Okbay et al., 2022), hypertension (Hoffmann et al., 2017), immune diseases (Johansson et al., 2019), neuropsychiatric disorders (Yao et al., 2021), and BMI (Tachmazidou et al., 2017). The gene discussed is MAD1L1; the disease is obesity due to melanocortin 4 receptor deficiency.