Background and aims Bronchopulmonary dysplasia (BPD) is an unfortunately common outcome following premature birth. Genetic factors influence BPD development but their role is part of a complex interaction with environmental factors. We postulated that alterations in the gene as well as imbalances in gene products may affect BPD development.
Methods The NIH human genome database was interrogated for previously identified gene polymorphisms that have been associated with neonatal respiratory conditions. Angiotensin converting enzyme (ACE) and surfactant proteins A-D gene candidates were selected based upon clinical plausibility for the study population. DNA was extracted from whole blood and Guthrie card specimens. Surfactant single nucleotide polymorphism (SNP) genotyping was arranged using the Taqman technique. ACE gene primers were obtained for the previously known insertion/deletion polymorphism and PCR analysis was performed.
Results 236 infants born prematurely survived to 28 days postnatal age and contributed to genotype analysis. 106 infants did not develop BPD and 130 infants did develop BPD (54 mild, 29 moderate, 47 severe). Both gestational age and birth weight were significantly different between those infants who did and did not develop BPD and predicted BPD development with an area under the ROC of 0.88 and 0.82 respectively. We demonstrated using multifactorial statistical analysis that the inclusion of the ACE genotype to a predictive statistical model of BPD development improves the predictive potential of the model (area under ROC curve 0.88).
Conclusion The presence of the ACE DD genotype is associated with a higher likelihood of developing BPD.