The most common reasons for erythrocytosis are acquired, due to somatic variants or various extrinsic factors that lead to reduced oxygen supply and thus stimulation of erythropoiesis, such as chronic pulmonary, cardiac, renal, hepatic diseases, erythropoietin (EPO)-secreting tumors, high-altitude living, smoking, sleep apnea, recombinant EPO, and androgen administration (McMullin, 2008; Lee and Percy, 2011; Bento, 2018). This evidence concerns the gene EPO and sleep apnea syndrome.