We report a case of a 63-year-old patient with psychiatric symptoms diagnosed with coexisting DiGeorge syndrome, Fahr syndrome and Turner syndrome. To our knowledge, this is the first reported case of coexistence of DiGeorge syndrome and mosaic Turner syndrome. Basal ganglia calcification, known as Fahr syndrome, may develop in patients with DiGeorge syndrome as a consequence of calcium-phosphate balance disturbances resulting from primary hypoparathyroidism. A deletion of chromosome 22q11.2 in DiGeorge syndrome, basal ganglia calcification and, according to some research, mosaic Turner syndrome independently can lead to psychiatric disorders. A leading clinical manifestation of the genetic diseases in our patient was long-term, drug-resistant depression with sleeping disorders and organic hallucinosis. Affective disorders led the patient to attempt suicide. The aim of the study was to highlight the importance of perceiving subtle findings which can lead to a diagnose of a genetic disease in a patient with mental health issues. We also discuss the predisposition to psychiatric disorders in DiGeorge syndrome, Turner syndrome and Fahr syndrome.