These findings suggest a non-gender-specific effect on MDD given the increased 4R allele presence in the MDD group (X2 = 12.48; df = 1; p < 0.001), even considering X-inactivation at the MAOA locus (X2 = 10.7,2; df = 1; p = 0.001) [33]. The gene discussed is MAOA; the disease is major depressive disorder.