title: Familial testicular torsion: a meta analysis suggests inheritance.
abstract: OBJECTIVE
  Familial occurrence of testicular torsion has been infrequently reported. To date, no systematic analysis has been published. We systematically analyzed the literature to elucidate the epidemiology, presentation, management, and whether the observed prevalence of testicular torsion in families is consistent with absence of inheritance and is randomly distributed.
  
  
  METHODS
  We searched electronic databases using keywords "testicular torsion", "spermatic cord torsion", "familial torsion" and "sibling torsion". Reports with genetically related first degree relatives were included in the analysis. Levene's nonparametric test was used to compare the variance of the age of presentation within families to that between different families to differentiate between familial predisposition and chance events.
  
  
  RESULTS
  Up to 10% of patients with testicular torsion have an affected first degree relative. We were able to reject the null hypothesis that the observed prevalence of testicular torsion is due to chance (p < 0.001). Family history is missed in at least 27% of affected families. There is a high incidence of bilateral testicular torsion in families (37%) and probands (17%) and a high concordance rate for bilaterality among monozygous twins.
  
  
  CONCLUSIONS
  Current evidence from clinical and animal studies suggests the presence of a genetically determined component in familiar testicular torsion. Increased awareness may lead to earlier clinical presentation and higher testicular salvage rates.
authors.affiliation: Phoenixville Urology Associates, 824 Main St Ste 203, Phoenixville, PA 19460, USA. alexuromd@gmail.com
authors.forename: Alex
authors.initials: A
authors.lastname: Shteynshlyuger
authors.forename: Junhua
authors.initials: J
authors.lastname: Yu
mesh_terms: D004200:Diseases in Twins / Q000235:genetics; D006801:Humans; D008297:Male; D013086:Spermatic Cord Torsion / Q000453:epidemiology / Q000235:genetics* / Q000628:therapy; D014430:Twins, Monozygotic