ADRA2A and small artery occlusion: In addition, the c.971_982del of rs61767072 of the adrenoceptor-α2 (ADRA2) gene was associated with CIs when patients had hypertension and hyperhomocysteinemia, and the c.145A>G (rs1801252) polymorphism of the ADRB1 gene was associated with small artery occlusion [82].