Table 2.
Frequency of Allelic Distribution for COMT, DRD2, and BDNF genes
| Gene (RSID) |
Allele | % observed | % expected | P Value |
|---|---|---|---|---|
|
COMT
(rs4680) |
A/A | 34 (43/128) | 30 | .0001 |
| G/A | 55 (71/128) | 40 | ||
| G/G | 11 (14/128) | 30 | ||
|
DRD2
(rs1076560) |
G/G | 63 (80/128) | 75 | .0215 |
| G/T | 34 (44/128) | 23 | ||
| T/T | 3 (4/128) | 2 | ||
|
BDNF
(rs6265) |
G/G | 68 (87/128) | 62 | .3144 |
| A/G | 28 (36/128) | 35 | ||
| A/A | 4 (5/128) | 3 |
Abbreviations: BDNF, brain-derived neurotrophic factor; COMT, catechol-O-methyltransferase; DRD2, dopamine receptor 2; RSID, reference single-nucleotide polymorphism cluster ID;
The observed values represent the percentage of allelic distribution in our sample of adults with low- and high-grade glioma. The expected values represent the Hardy–Weinberg equilibrium for the percentage of allelic distribution in a mixed gender/age population for the BDNF allele though not for the COMT or DRD2 alleles.