Table 2.
The Results of Measurement of DHFR Activity and Folate Vitamers in the Proband on Folinic Acid Therapy and in His Heterozygous Parents
| Assay (Units) | Reference range | Patient | Mother | Father | Control 1 | Control 2 |
|---|---|---|---|---|---|---|
| DHFR activity (nmol THF/hr/mg protein) | NA | 1.5 ↓↓ | 59.7 ↓ | 52.9 ↓ | 154.7 | 149.6 |
| MTHF (nmol/l) | 95–470 | 169 | 117 | 43 ↓ | NA | NA |
| NonmethylTHF (nmol/l) measured as THF + methylene-THF + methenyl-THF + formyl-THF |
0–67 | 77 ↑ | 9.8 | 45 | NA | NA |
| Dihydrofolate + folic acid (nmol/l) | 0 | 31 ↑↑ | 0 | 0 | NA | NA |
NA, not available; THF, tetrahydrofolate; ↑, values above the reference range; ↓, values below the reference range. Double arrows indicate values that are severely abnormal.