Mutation screening of BMP4 and Id2 genes in Chinese patients with congenital ureteropelvic junction obstruction

Abstract

Ureteropelvic junction obstruction (UPJO) is the most common congenital anomaly of the urinary tract. Evidence has shown that BMP4 and Id2 play crucial roles in nephrogenesis, alterations of which may cause ureteral developmental anomalies. Here, we directly sequenced the coding sequences in BMP4 and Id2 genes of 108 unrelated Chinese patients with ureteropelvic junction stenosis. One missense mutation c.485G> A (p.R162Q) in BMP4 and two synonymous mutations (c.1167T> C in BMP4 and c.108A> G in Id2) were detected in three cases. None of these variations were present in the 150 normal controls. Comparative amino acid sequence alignments of BMP4 in humans and other vertebrate orthologs show that p.R162 located to a highly conserved amino acid residue. Moreover, computational analysis predicted that R162Q probably infect the function of BMP4 protein. The mutation c.485G> A in BMP4 might be one of the causes of human UPJO. Further functional studies are required to validate the association between this variation and UPJO. Otherwise, Id2 mutations do not seem to be involved in this disease.