Gene patents break down generally into four categories: diagnostics, functional use, process and compositions of matter. These patents might be on a single gene, but more often than not, they are on a process involving genetic material or on a small strand of linked genes, and they generally focus on the parts of genes involved in the production of proteins.
When it comes to diagnostics, gene researchers are looking to patent methods that test for genetic differences or abnormalities. These types of patents are occasionally referred to as disease gene patents, because they are most often associated with spotting genetic markers involved in ailments such as cancer, Alzheimer's disease and cystic fibrosis. Things get complicated in this category of gene patents because one gene can have many different mutations, or one test can analyze different genes for the same disease -- and all of the different combinations of engineered mutations and tests can be patented.
Functional use patents stem from research that discovers the roles played by various genes in causing disease in the body or in regulating bodily functions. These patents are typically issued for drugs which affect the functioning of genes.
Process patents are relatively self-explanatory and are used to protect a method by which genes are extracted or manipulated. In the furor surrounding gene patenting, these types of patents are relatively benign, as they patent a process rather than actual human genetic material.
Composition of matter patents are filed to protect "inventions" that generally stem from combining different genetic material and are typically filed for drugs and vaccines such as insulin and human growth hormone (HGH). This type of patent is at the heart of much of the legal controversy surrounding genetic patents, as we'll see in the next section.