GSTM1 and Patent ductus arteriosus: We also found that the incidences of Hb × SpO2 < aaHb were higher in children with patent ductus arteriosus (26.2%) or transposition of great arteries (46.6%) and were lower in children with aortopulmonary collateral arteries (17.5%) or clubbed fingers or toes (13.9%).