 Our bodies are made out of trillions of cells. Each cell contains all of the genetic information necessary for us to develop from one single cell into adults. And this information is encoded in our DNA, in specific sequences or genes. Our DNA also contains the information responsible for our body to function correctly, and our chances of developing a specific disease. In order to fit this immense amount of information in each cell, our DNA is packaged and organized in 46 individual chromosomes. Chromosomes are thread-like structures formed of linear DNA coiled around proteins, which give structural support. But what do the ends of chromosomes look like? At each end are thousands of repeats of the same DNA sequence bound by a special set of proteins called shelterin, which together form a structure called the telomere. Telomeres are like caps which protect the end of chromosomes from breaking or fusing with other chromosomes. Every time a cell divides, each chromosome replicates, and the two copies are distributed to each daughter cell to ensure the genetic information is passed on. However, the cell machinery cannot copy the very end of linear DNA, therefore every time a cell divides, the telomeres become shorter and shorter. When they reach a critically short length, the cell can't divide any longer. Very short telomeres instruct cells to seize division, and this stimulates a process of biological aging or cell death. So how does a cell make sure its genetic information is not lost with every division? This problem is solved by an enzyme called telomerase. Telomerase is able to extend DNA by adding telomeric DNA repeats to the ends of chromosomes, maintaining all of its genetic information and allowing the cell to keep dividing. We normally find high levels of telomerase only in those cells that divide frequently, such as cells during fetal development, stem cells in tissues such as the bone marrow, which produces blood cells, the digestive tract, as well as in cancer cells, which need to keep multiplying and thus need to keep their telomeres replenished. Sometimes there are changes or mutations in our DNA which affect the function of different genes. In telomere biology disorders or TBDs, mutations appear in the factors which play an important role in extending, replicating, or maintaining telomere length or structure. Different names have been used to describe the different syndromes, but what they all have in common is that cells have abnormally short telomeres. So far, 14 genes have been identified as being associated with TBDs, but there are individuals where the genes affected still hasn't been identified. What are the symptoms of TBDs? Because all cells have telomeres, many organs throughout the body can be affected by short telomeres, and the symptoms can vary from individual to individual. Although some, like the bone marrow and the digestive tract, are extremely sensitive to telomere length. Some individuals have abnormal finger and toenails, white spots in their mouth called leukoplakia, and abnormal skin pigmentation, known as the mucocutaneous triad. The immune system, lung, and liver may be affected, and certain forms of cancer may occur. Additional information can be found in Deskeratosis congenital and telomere biology disorders, diagnosis and management guidelines. What are the treatments for TBDs? The current treatments focus on organ-specific life-saving interventions, such as bone marrow or lung transplantation. With time and understanding, these have become safer and more accessible to individuals with TBDs. As science evolves, there is more focus on how we can fix the defects in telomerase activity or telomere length prior to the onset of organ failure. More support and funding are required in order to do more research to find a cure for TBDs. Individuals with TBDs and their families can connect through Team Telomere as a community, find resources and access to treatment, and learn how to fund research. This, along with the work of the Clinical Care Consortium for Telomere-associated ailments, a group of physicians and scientists from around the world that are working together by doing research and to improve the diagnosis and treatment of TBD, gives us hope for the future. For more information, reach out to info at teamtelomere.org.