In the analyzed ten archaic human genome-wide data, there were nine pathogenic mutations in five genes established to be associated with monogenic diseases: five mutations in the PAH gene associated with the rare inherited disorder phenylketonuria, and one mutation each in the HBB gene causing β-thalassemia major, the SRD5A2 gene associated with disturbances in male’s sexual development, the ASPA gene associated with Canavan Disease, and the MAOA gene associated with Brunner Syndrome in males exclusively. The gene discussed is MAOA; the disease is Brunner syndrome.