First, development is controlled by genes inherited from the parents.

To have the disease, you must inherit the gene from each parent.

Multiple genes inherited from each parent determine a person's eye color.

If a child inherits the gene from both parents, they may develop Wilson's disease.

A son cannot inherit the defective gene from his father.

Thus, an alteration must occur in each of the two genes inherited from a person's mother and father.

The chance a child will inherit the mutated gene is 50%.

The disorder, which is caused by a defective gene inherited from both parents, can lead to death before age 20.

Some people inherit genes that trigger too much cholesterol production.

Sons or daughters have a 50 percent chance of inheriting the gene from the parent who has it.