Four new variants of the alpha2-globin gene without clinical or hematologic effects: Hb Park Ridge [alpha9(alpha7)Asn-->Lys (alpha2)], Hb Norton [alpha72(EF1)His-->Asp (alpha2)], Hb Lombard [alpha103(G10)His-->Tyr (alpha2)], and Hb San Antonio [A113(GH2)Leu-->Arg (A2)].