Positive association between two polymorphic sites (+134 insA/delA and G198T) of the endothelin-1 gene and chronic obstructive pulmonary disease. A case-control study

Within the COPD patient group carriers of the GT genotype had more often mild or moderate COPD compared to patients carrying the GG genotype (P = 0.004). Haplotypic distribution revealed that carriers of the 4A:T and 4A:G haplotypes were in increased risk of COPD development. Additionally, patients with the 3A:G haplotype were in increased risk of developing severe COPD, whereas patients with the 3A:T and 4A:T had most probably mild-moderate COPD.