The importance of BMP4 gene mutation in patients with renal and urinary tract congenital anomaly (CAKUT)

Objective: Congenital anomalies of kidney and urinary system (CAKUT) refers to a large group of diseases, including structural malformations, caused by defects in the morphogenesis of the kidneys and urinary tract, resulting in increased morbidity and mortality in childhood. Data related with genetic factors involved in the pathogenesis of CAKUT is inadequate. In this study, we aimed to investigate the frequency and importance of BMP4 mutation in patients with CAKUT. Material and method: Ninety six patients with CAKUT were included to the study. Patients ages were between 0-18 years and were followed in Başkent University Ankara Hospital Pediatric Nephrology Unit. The healthy control group consisted of 96 patients of similar age and gender and did not have any urinary system anomalies. Variations in the BMP4 gene were examined in all patients with DNA analysis. Results: 46 (47.9%) male and 50 (52.1%) female were included in the study. Median age was 6.4 years (min-max: 0.1-18) in the patient group and 6.1 years (min-max: 0.5-18) in the control group. Compared with the control group, the sex and age were similar. In patients with CAKUT, the BMP4 frequency was 2.2 times higher than the control group (p <0.05). The rate of variation in the BMP4 gene among patients with CAKUT was found to be 39.6%. There were 12 variations in the BMP4 gene. Variant c.450G>C (pN150K) was found in 4 patients (4.1%) in the CAKUT group while it was not present in the control group. All of these 4 patients were diagnosed with hypoplasia/dysplasia. Conclusion: Our study showed that variations in the BMP4 gene play a role in the pathogenesis of CAKUT, especially in the development of hypoplasia/dysplasia. However, it is thought that the interaction of different genes in this matter may play a role in the emergence of CAKUT. Further studies are needed in this regard.