Abstract
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.
| Translated title of the contribution | Cryptorchidism concordance in monozygotic and dizygotic twin brothers, full brothers, and half-brothers |
|---|---|
| Original language | English |
| Journal | Fertility and Sterility |
| Volume | 93 |
| Issue number | 1 |
| Pages (from-to) | 124-9 |
| Number of pages | 6 |
| ISSN | 0015-0282 |
| DOIs | |
| Publication status | Published - 1 Jan 2010 |