Purpose: Hypospadias, when the urethra opens on the underside of the penis, is a common malformation that occurs in about 1/300 boys. The etiology of hypospadias is unknown but several lines of evidence indicate that it is caused by the combined influence of genetic and environmental factors. To identify chromosomal loci involved in the pathogenesis of hypospadias we performed genome-wide linkage analysis.
Materials and methods: A total of 69 families with at least 2 members with hypospadias were genotyped with 360 microsatellite markers and analyzed with a nonparametric affected relative pair method. Of them 58 were of Swedish origin and 11 were from the Middle East.
Results: Suggestive linkage was found at the 4 chromosome regions 9q22 (in all families), 2p11, 10p15 and 10q21 (in Swedish families).
Conclusions: These results provide a basis for outlining the genetic background of hypospadias.