Control Asthma COPD
  No % No % No %
Genotype            
CC 11 18.3 26 52.0 15 37.5
CT 40 66.7 22 44.0 21 52.5
TT 9 15.0 2 4.0 4 10.0
χ2 (p)     14.976*(0.001) 4.642 (0.098)
         
Allele frequency            
C 51 51.0 48 52.2 36 59.0
T 49 49.0 44 47.8 25 41.0
χ2 (p)   0.026 (0.871) 0.980 (0.322)
χ2: Chi square test between control and other groups. *: Statistical significance at p ≤ 0.05
Table 2: The genotype and allele frequencies of CD40 − 1C/T among the three studied groups.