Identification of new genes for branchio-oto-renal syndrome. Branchio-oto-renal syndrome (BOR) is an autosomal dominant developmental disorder characterized by the association of hearing loss, renal anomalies, and branchial arch defects. Branchio-otic syndrome (BO) is a related disorder without renal anomalies. Dominant mutations in the human ortholog of the Drosophila eyes absent gene (EYA1) cause BOR and BO. By total genome search for linkage in a large kindred of 18 individuals affected with BO, we mapped a new gene locus (BOS3) to chromosome 14q21. Within the 33 Mb critical genetic interval we located the SIX1 gene, which is known to play a role in the PAX-EYA-SIX hierarchy of developmental regulation in the organogenesis of kidney and ear. By direct sequencing we identified 3 different SIX1 mutations in this kindred and in 2 additional kindred with BOR/BO, thus identifying SIX1 as a new gene causing BOR and BO. By functional analysis we show that all 3 mutations interfere with Eya1-Six1 protein-protein interaction, and that the two homeodomain mutations impede Six1-DNA binding. In addition, we generated first evidence that SOX13 mutations may be found in patients with BOR/BO. The C. elegans INTERACTOME project recently confirmed eya-1/six-1 interaction and identified in this model organism many further eya-1 interaction partners, the human orthologs of which represent excellent candidate genes for BOR/BO. This proposal is aimed at the identification of further genes, mutations in which cause BOR/BO and at the functional characterization of SIX1, SOX13, and related genes within the context of BOR/BO and kidney and ear development in humans. Specifically, we propose to: 1) Detect further mutations in the newly identified BOR/BO genes SIX1 and SOX13, and study their functional role for kidney and ear developmental defects in BOR/BO. 2) Identify further genes as responsible for BOR/BO, using as candidate genes members of the Eya1/Six1 transcriptional complex and eya-1 binding partners derived from the C. elegans INTERACTOME data, and study genotype/phenotype relationships. 3) Identify a new gene causing BO by positional cloning in a new large BOR/BO kindred. Identification of new genes causing branchio-oto-renal syndrome will offer new insights into the pathomechanisms of hearing defects, urinary tract malformations as well as kidney and ear development.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD045345-05
Application #
7555075
Study Section
Mammalian Genetics Study Section (MGN)
Program Officer
Coulombe, James N
Project Start
2005-01-01
Project End
2009-12-31
Budget Start
2009-01-01
Budget End
2009-12-31
Support Year
5
Fiscal Year
2009
Total Cost
$315,451
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Pediatrics
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Kohl, Stefan; Chen, Jing; Vivante, Asaf et al. (2016) Targeted sequencing of 96 renal developmental microRNAs in 1213 individuals from 980 families with congenital anomalies of the kidney and urinary tract. Nephrol Dial Transplant 31:1280-3
Saisawat, Pawaree; Tasic, Velibor; Vega-Warner, Virginia et al. (2012) Identification of two novel CAKUT-causing genes by massively parallel exon resequencing of candidate genes in patients with unilateral renal agenesis. Kidney Int 81:196-200
Harville, H M; Held, S; Diaz-Font, A et al. (2010) Identification of 11 novel mutations in eight BBS genes by high-resolution homozygosity mapping. J Med Genet 47:262-7
Ashraf, Shazia; Hoskins, Bethan E; Chaib, Hassan et al. (2010) Mapping of a new locus for congenital anomalies of the kidney and urinary tract on chromosome 8q24. Nephrol Dial Transplant 25:1496-501
Jensen, Daniel R; Martin, Donna M; Gebarski, Stephen et al. (2009) A novel chromosome 19p13.12 deletion in a child with multiple congenital anomalies. Am J Med Genet A 149A:396-402
Hildebrandt, Friedhelm; Heeringa, Saskia F; Rüschendorf, Franz et al. (2009) A systematic approach to mapping recessive disease genes in individuals from outbred populations. PLoS Genet 5:e1000353