Cryptorchidism concordance in monozygotic and dizygotic twin brothers, full brothers, and half-brothers

Research output: Contribution to journalJournal articleResearchpeer-review

  • Morten Søndergaard Jensen
  • Gunnar Toft
  • Ane Marie Thulstrup
  • Tine Brink Henriksen
  • Jørn Olsen
  • Kaare Christensen
  • Jens Peter Bonde

View graph of relations

OBJECTIVE: To study concordance rates of cryptorchidism (undescended testis) in pairs of boys with varying family structure, to evaluate the risk contribution from the intrauterine environment and genetic factors. DESIGN: Population based study of 1,024,500 Danish boys born from January 1, 1973 to December 31, 2004. Classic twin method and computerized square dance design. SETTING: Hospitals and outpatient clinics. PATIENT(S): Six groups of boy pairs: boys with no relation, paternal half-brothers, maternal half-brothers, full brothers, dizygotic twin brothers, and monozygotic twin brothers. INTERVENTION(S): Observational study. MAIN OUTCOME MEASURE(S): Status on each individual regarding cryptorchidism and orchiopexy from the Danish National Patient Register. RESULT(S): Concordance rates of cryptorchidism in the groups were as follows: boys with no relation 3.2% (95% confidence interval 2.7%-3.6%), paternal half-brothers 3.4% (2.3%-4.7%), maternal half-brothers 6.0% (4.5%-7.7%), full brothers 8.8% (8.3%-9.8%), dizygotic twin brothers 24.1% (16.0%-33.6%), and monozygotic twin brothers 27.3% (15.5%-41.2%). CONCLUSION(S): The concordance rate was higher in maternal than in paternal half-brothers, and much higher but of equal magnitude in both twin groups. The findings strongly support that the intrauterine environment and maternal inheritance are contributing to the occurrence of cryptorchidism.
JournalFertility and Sterility
Issue number1
Pages (from-to)124-129
Number of pages5
Publication statusPublished - 1 Jan 2010

    Research areas

  • Adolescent, Adult, Child, Child, Preschool, Cryptorchidism, Denmark, Environment, Genetic Predisposition to Disease, Heredity, Humans, Logistic Models, Male, Odds Ratio, Orchiopexy, Pedigree, Registries, Risk Assessment, Risk Factors, Twins, Dizygotic, Twins, Monozygotic, Young Adult