Chapter 12 of a two hour 16 part presentation. Running time 04:06. This chapter explores how scientists use the human genome to make the connection between a disease and a gene. Scientists use families to find the specific genes that cause a particular disease and Iceland is a perfect place to do that. As the company DeCODE gears up to create a giant DNA database using the Icelandic family tree and medical information, ethical questions arise of who should be able to use such information.