Advantage and Disadvantages of Linkage Studies. Linkage studies are good for localising areas of disease risk across the genome. They can also be used to study multiple genetic markers simultaneously. There are however several disadvantages to linkage studies. Researchers need to identify a large number of families with several affected generations. If the disease is of late-onset with a high mortality, finding families with more than one affected generation will be difficult. Linkage studies are less helpful for complex traits, such as diabetes where multiple genes are important in disease causation.