Population | Phenotype | No. of cases/controls | Risk allele | Protective allele | Ref | |
Caucasian | Canada | COPD | 75/64 | – | GC2 | 61 |
Canada | COPD | 104/413 | – | GC2 | 60 | |
Iceland | COPD Chronic bronchitis | 112/183 48/183 | – GC1F | – GC2 | 110 | |
Russia | COPD | 298/237 | – | – | 56 | |
USA | COPD | 127 families and 304/441 | – | – | 54 | |
Denmark | Rapid decline of FEV1 | 283/308 | – | – | 55 | |
Asian | Tatar | COPD | 298/237 | GC1F | GC2 | 56 |
Japan | COPD Rapid decline of FEV1Emphysema | 113/88 86/21 85/88 | GC1F | – | 57 | |
Japan | COPD Diffuse panbronchiolitis | 63/82 82/82 | GC1F | – | 58 | |
China | COPD | 69/52 | GC1F | – | 59 |
The table summarises studies of functional GC variants in COPD phenotypes. Since some of the studies have considered related, albeit different, COPD phenotypes, or have used different severity criteria, meta-analysis has not been performed. There have been three studies in Caucasians reporting that GC2 homozygotes were protected from COPD, but also three negative studies. In Asian subjects there have been four studies reporting GC1F (particularly homozygotes) to be susceptible to COPD, and one report of GC2 acting as a protective variant. It should be noted that the Tatar population in whom this study was performed, whilst ethnically Asian (coming from Mongolia), are relatively heterogeneous in modern Russia, where the study was performed. Ancestral markers to determine racial admixture were not checked, so this population is likely to contain both Asian and Caucasian elements.
FEV1, forced expiratory volume in 1 s.