Table 3.
Allelic variants of XO, TPMT and ITPA genes and their frequencies among (a) 19 paediatric ALL patients (n = 38 alleles) and (b) 35 IBD patients (n = 70 alleles)
| Allelic variants | Alleles (n) | Allelic frequency (%) | Heterozygotes/homozygotes (n) | Heterozygotes/homozygotes (%) |
|---|---|---|---|---|
| (a) ALL patients | ||||
| XO A1936→G | 1 | 2.6 | 1/0 | 5.3/0 |
| XO A2107→G | 1 | 2.6 | 1/0 | 5.3/0 |
| TPMT*3A | 1 | 2.6 | 1/0 | 5.3/0 |
| TPMT*3B | 0 | 0 | – | – |
| TPMT*3C | 2 | 5.3 | 2/0 | 10.5/0 |
| ITPA C94→A | 3 | 7.9 | 3/0 | 15.8/0 |
| ITPA IVS2+21A→C | 4 | 10.5 | 2/1 | 10.5/5.3 |
| (b)IBD patients | ||||
| XO A1936→G | 3 | 4.3 | 3/0 | 8.5/0 |
| XO A2107→G | 3 | 4.3 | 3/0 | 8.5/0 |
| TPMT*3A | 4 | 5.7 | 4/0 | 11.4/0 |
| TPMT*3B | 0 | 0 | – | – |
| TPMT*3C | 0 | 0 | – | – |
| ITPA C94→A | 4 | 5.7 | 2/1 | 5.7/1.4 |
| ITPA IVS2+21A→C | 9 | 12.9 | 5/2 | 14.3/2.9 |
XO, xanthine oxidase; TPMT, thiopurine S-methyl transferase; ITPA, inosine triphosphatase; ALL, acute lymphoblastic leukaemia; IBD, inflammatory bowel disease.