This is a complete guide. Please contact me if you need anything more specific or know of a better source for something I've missed.
1. Lighter skin is an inherited condition that is passed on by both parents. If you are a parent of light skin, you will have inherited it. So if your dad is light skin, and your mom is light skin, your dad could have the same problem as you, or he could have a different problem. The most common light skin disorder is albinism. Albinism is when the skin pigment is dark, or dark in color. If a person is not albino, he or she may have dark skin due to a number of reasons, but usually because of a genetic mutation. One of the genetic causes for albinism is called Turner's Syndrome. It is an inheritance disorder caused by a particular gene, called the PINK1 gene. PINK1 is also known as the gene that gives the body its coloration, or pigment. If you have the gene, you are born with darker skin, and this will prevent you from tanning, and your skin will be darker. This is also called an albino. The genetic mutation that causes the disorder affects only one in a billion people, and that is why you can find people who have it and don't know it.