Male; age, 54 years; Hb, 182 g/L; Ht, 0.53; RBC, 6.24 × 1012; EPO 6.1 IU/L; platelets, 271 × 109/L; smoking; mild sleep apnea; asthma; Hashimoto’s thyroiditis, phlebotomy; possible positive family history, brother also similar symptoms. Here, GSTM1 is linked to sleep apnea syndrome.