Hypospadias is a common birth defect in boys where the opening of the urethra is not located at the tip of the penis. The urethra is the tube that carries urine from the bladder to the outside of the body. It is estimated that hypospadias affects about 1 in every 200 boys. The condition is most often diagnosed during a physical exam shortly after birth.
While all the causes of hypospadias are not known, problems with hormones are believed to play a role (You might want to just say the exact cause is unknown - saying the problem is with hormones may lead parents to be concerned that their boys will have some life-long hormone issue). In boys with hypospadias, the penis doesn't look normal and it doesn't work well. For example, some boys with hypospadias have a curved penis. This can cause problems like abnormal spraying of urine and having to sit down to urinate (Actually the abnormal urethral opening causes the spraying and need to sit. The curvature, if severe, can be an issue for sexual function).
Treatment for hypospadias depends on the type of defect your boy has. In most cases, surgery will be needed to correct the defect. (Needed is a bit strong. Most hypospadias is mild and actually is more an aesthetic issue than a functional one unless severe. Therefore I would change "needed" to "recommended" or "considered") If surgery is needed (again - "considered" or "elected"), it's usually done when the baby is between the ages of 6-12 months old.
Some of the repairs performed during the surgery may include placing the opening of the urethra in the right place, correcting the curve in the penis, and repairing the skin around the opening of the urethra (not sure what this last means - there is no "correction of the skin around the urethra". It is more removing the partial foreskin and moving the skin around to cover the underside of the penis). Because your doctor might need to use the foreskin of the penis to make some of the repairs, a boy with (I would add the word "significant" as we actually do go ahead with circumcision for mild cases) hypospadias should not be circumcised.
If your son has hypospadias, work with a pediatric urologist to discuss the best plan of action.