Inherited and acquired thrombophilic abnormalities and biologic markers in 40 children with MPDs
| Thrombophilic abnormalities . | Patients with thrombophilic alterations/evaluated patients (%) . | Thrombocythemic patients/evaluated patients (n = 31) . | Polycythemic patients/evaluated patients (n = 9) . |
|---|---|---|---|
| MTHFRC677T mutation | 28/40 (70%) | 22/31 (71%) | 6/9 (67%) |
| Homozygous | 1/28 | 1/22 | |
| Heterozygous | 27/28 | 21/22 | 6/6 |
| Combined with: | 13/27 (48%) | 9/21 (43%) | 4/6 (66.5%) |
| FVL | 2/13 | 2/9 | |
| FIIG20210A mutation | 1/13 | 1/9 | |
| FIIG20210A mutation + prolonged SCT ratio | 1/13 | 1/9 | |
| Prolonged SCT ratio | 1/13 | 1 | |
| Prolonged SCT ratio + high HCY | 1/13 | 1 | |
| High HCY | 2/13 | 1/9 | 1 |
| Low PC | 2/13 | 2/9 | |
| Low PC + PS | 1/13 | 1 | |
| Low PS | 2/13 | 2/9 | |
| Heterozygous FVL mutation | 2/40 (5%) | 2/31 (6.5%) | 0 |
| Combined with heterozygous MTHFRC677T | 2/2 | 2/2 | |
| Heterozygous FIIG20210A | 3/40 (7.5 %) | 3/31 (9.5%) | 0 |
| Combined with heterozygous MTHFRC677T | 2/3 | 2/3 | |
| Prolonged SCT ratio | 5/39 (13%) | 1/30 (3%) | 4/9 (44.5%) |
| Combined with other abnormalities | 3/5 | 1/1 | 3/4 |
| Prolonged dRVVT ratio | 1/38 | 0 | 1/9 (11%) |
| Combined with prolonged SCT ratio | 1/1 | 1/1 | |
| Low functional PC level | 3/40 (7.5%) | 2/31 (6.5%) | 1/9 (11%) |
| Combined with other abnormalities | 3/3 | 2/2 | 1/1 |
| Low free PS level | 5/40 (12.5%) | 3/31 (9.5%) | 2/9 (22%) |
| Combined with other abnormalities | 3/5 | 2/3 | 1/2 |
| High HCY level | 3/29 (10%) | 1/20 (5%) | 2/9 (22%) |
| Combined with other abnormalities | 3/3 | 1/1 | 2/2 |
| No thrombophilic abnormalities | 7/40 (17%) | 7/31 (22.5%) | 0 |
| Thrombophilic abnormalities . | Patients with thrombophilic alterations/evaluated patients (%) . | Thrombocythemic patients/evaluated patients (n = 31) . | Polycythemic patients/evaluated patients (n = 9) . |
|---|---|---|---|
| MTHFRC677T mutation | 28/40 (70%) | 22/31 (71%) | 6/9 (67%) |
| Homozygous | 1/28 | 1/22 | |
| Heterozygous | 27/28 | 21/22 | 6/6 |
| Combined with: | 13/27 (48%) | 9/21 (43%) | 4/6 (66.5%) |
| FVL | 2/13 | 2/9 | |
| FIIG20210A mutation | 1/13 | 1/9 | |
| FIIG20210A mutation + prolonged SCT ratio | 1/13 | 1/9 | |
| Prolonged SCT ratio | 1/13 | 1 | |
| Prolonged SCT ratio + high HCY | 1/13 | 1 | |
| High HCY | 2/13 | 1/9 | 1 |
| Low PC | 2/13 | 2/9 | |
| Low PC + PS | 1/13 | 1 | |
| Low PS | 2/13 | 2/9 | |
| Heterozygous FVL mutation | 2/40 (5%) | 2/31 (6.5%) | 0 |
| Combined with heterozygous MTHFRC677T | 2/2 | 2/2 | |
| Heterozygous FIIG20210A | 3/40 (7.5 %) | 3/31 (9.5%) | 0 |
| Combined with heterozygous MTHFRC677T | 2/3 | 2/3 | |
| Prolonged SCT ratio | 5/39 (13%) | 1/30 (3%) | 4/9 (44.5%) |
| Combined with other abnormalities | 3/5 | 1/1 | 3/4 |
| Prolonged dRVVT ratio | 1/38 | 0 | 1/9 (11%) |
| Combined with prolonged SCT ratio | 1/1 | 1/1 | |
| Low functional PC level | 3/40 (7.5%) | 2/31 (6.5%) | 1/9 (11%) |
| Combined with other abnormalities | 3/3 | 2/2 | 1/1 |
| Low free PS level | 5/40 (12.5%) | 3/31 (9.5%) | 2/9 (22%) |
| Combined with other abnormalities | 3/5 | 2/3 | 1/2 |
| High HCY level | 3/29 (10%) | 1/20 (5%) | 2/9 (22%) |
| Combined with other abnormalities | 3/3 | 1/1 | 2/2 |
| No thrombophilic abnormalities | 7/40 (17%) | 7/31 (22.5%) | 0 |
MTHFRC677T indicates methylentethrahydrofolate reductase; PC, protein C; PS, protein S; HCY, homocysteine; SCT, silica clotting time; and dRVVT, diluted Russel viper venom time.