Bronchopulmonary dysplasia (BPD) is a chronic lung disease that affects a ratio of up to 20-30% of infants prematurely born before 30rd week. Delay of starting to speak, cerebral palsy and cognitive disorders may be seen in infants suffering from this disease. Although all the evidence found on the specific mediators and pathways that regulate the mechanism by studies made to understand the pathophysiologic mechanism, there hasn't been any remarkable progress on preventing the development of BPD in new-born infants born below 1500gr body weight. BPD is still one of the most important morbidity and mortality reasons in premature infants. There is a need of further studies to understand the genetic background of BPD specific to different populations, to identify polymorphisms related with the disease and for developing genetic methods for early the diagnose of the disease.

With this purpose, first of all polymorphisms related with BPD and those which are related with similar other lung diseases will be investigated. DNA samples derived from blood samples of 200 patients (100 BPD infant and 100 control) will be examined for polymorphisms in specific genes that are chosen in the light of the prior literature scanning. To the investigators' knowledge, this will be the first study of a broad scanning of polymorphisms related with BPD in Turkish population.

Bronchopulmonary dysplasia is a chronic lung disease that affects a ratio of up to 20-30% of infants prematurely born before 30rd week. Delay of starting to speak, cerebral palsy and cognitive disorders may be seen in infants suffering from this disease. Although all the evidence found on the specific mediators and pathways that regulate the mechanism by studies made to understand the pathophysiologic mechanism, there hasn't been any remarkable progress on preventing the development of BPD in new-born infants born below 1500gr body weight. BPD is still one of the most important morbidity and mortality reasons in premature infants. There is a need of further studies to understand the genetic background of BPD specific to different populations, to identify polymorphisms related with the disease and for developing genetic methods for early the diagnose of the disease.

With this purpose, first of all polymorphisms related with BPD and those which are related with similar other lung diseases will be investigated. DNA samples derived from blood samples of 200 patients (100 BPD infant and 100 control) will be examined for polymorphisms in specific genes that are chosen in the light of the prior literature scanning. To the investigators' knowledge, this will be the first study of a broad scanning of polymorphisms related with BPD in Turkish population.

Inclusion Criteria:

• infants born under 30 gestational week
• infants with bronchopulmonary displasia

Exclusion Criteria:

• major congenital abnormalities
• lack of data
• parents don't agree with informed consent