title: Genetic basis of prune belly syndrome: screening for HNF1β gene.
abstract: OBJECTIVE
  Although the cause of prune belly syndrome is unknown, familial evidence suggests a genetic component. Recently 2 nonfamilial cases of prune belly syndrome with chromosome 17q12 deletions encompassing the HNF1β gene have made this a candidate gene for prune belly syndrome. To date, there has been no large-scale screening of patients with prune belly syndrome for HNF1β mutations. We assessed the role of HNF1β in prune belly syndrome by screening for genomic mutations with functional characterization of any detected mutations.
  
  
  METHODS
  We studied patients with prune belly syndrome who were prospectively enrolled in our Pediatric Genitourinary DNA Repository since 2001. DNA from patient samples was amplified by polymerase chain reaction, sequenced for coding and splice regions of the HNF1β gene, and compared to control databases. We performed functional assay testing of the ability of mutant HNF1β to activate a luciferase construct with an HNF1β DNA binding site.
  
  
  RESULTS
  From 32 prune belly syndrome probands (30 males, 2 females) HNF1β sequencing detected a missense mutation (V61G) in 1 child with prune belly syndrome. Absent in control databases, V61G was previously reported in 2 patients without prune belly syndrome who had congenital genitourinary anomalies. Functional testing showed similar luciferase activity compared to wild-type HNF1β, suggesting the V61G substitution does not disturb HNF1β function.
  
  
  CONCLUSIONS
  One genomic HNF1β mutation was detected in 3% of patients with prune belly syndrome but found to be functionally normal. Thus, functionally significant HNF1β mutations are uncommon in prune belly syndrome, despite case reports of HNF1β deletions. Further genetic study is necessary, as identification of the genetic basis of prune belly syndrome may ultimately lead to prevention and improved treatments for this rare but severe syndrome.
authors: Department of Urology, University of Texas Southwestern, Dallas, Texas, USA.
authors: Candace F
authors: CF
authors: Granberg
authors: Steven M
authors: SM
authors: Harrison
authors: Daniel
authors: D
authors: Dajusta
authors: Shaohua
authors: S
authors: Zhang
authors: Sachin
authors: S
authors: Hajarnis
authors: Peter
authors: P
authors: Igarashi
authors: Linda A
authors: LA
authors: Baker
mesh_terms: D005260:Female; D051539:Hepatocyte Nuclear Factor 1-beta / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D011446:Prospective Studies; D011535:Prune Belly Syndrome / Q000235:genetics*
chemical_list: C496495:HNF1B protein, human; D051539:Hepatocyte Nuclear Factor 1-beta