What causes hypospadias/epispadias?
Until 8 to 10 weeks of development, embryos have neither male nor female sex organs and genitalia, but instead have a genital tubercle, genital folds and genital swellings. The default developmental pathway is female development, with genital folds becoming labia minora, the tubercle forming the clitoris, and the genital swellings forming the labia majora. However, male hormones (testosterone and dihydrotestosterone, or DHT) secreted by the male embryo beginning around 10 weeks of development alter the default developmental pathway. The male hormones cause the genital swelling to create the scrotum, the genital folds to fuse together to become the shaft of the penis, and the genital tubercle to form the glans or tip of the penis. Normally, in male development, the genital folds fuse completely so that the penis completely surrounds the urethra all the way to the tip. Hypospadias/epispadias results when the genital folds fail to fuse properly, leaving part of the penis open and the uret
