Missense mutations in TNXB as a cause of VUR Missense mutations in TNXB as a cause of VUR. (A) Exons and protein domains of TNXB. (B and C) Missense heterozygous mutation exon 29. 9770 C>T T3257I found in the index family with hereditary VUR; this mutation is conserved in evolution. Missense mutations in TNXB as a cause of VUR. (A) Exons and protein domains of TNXB. (B and C) Missense heterozygous mutation exon 29. 9770 C>T T3257I found in the index family with hereditary VUR; this mutation is conserved in evolution. (D and E) Another kindred with VUR was found to have G1331R mutation in exon 10; this mutation is also conserved in evolution. Rasheed A. Gbadegesin et al. JASN 2013;24:1313-1322 ©2013 by American Society of Nephrology