Preliminary screening showed that there were 22 mutation sites in at least two HT patients and 16 corresponding genes in patients with HT as follows: TPO, SLC4A3, TP63, CD74, VEGFA, IL17A, SLC26A4, NOS3, TG, RET, MKI67, VDR, PSMD9, MUC16, XRCC1, AR. Here, SLC4A3 is linked to hematocrit.