The percentage of deoxyhemogolobin decreased after PFO closure (2.72 ± 0.53 versus 1.78 ± 0.37, p = 0.017), while the percentage of oxyhemoglobin, carbohemoglobin and methemoglobin, and concentration of total hemoglobin had no significant changes. The gene discussed is HBG2; the disease is Patent foramen ovale.