Talking rare diseases with UMN
Thursday, February 28, is Rare Disease Day. According to the National Institutes of Health, there are 7,000 known rare diseases that collectively affect approximately 30 million in the United States. In Minnesota, more than 50,000 individuals are affected by a rare disease.
Troy Lund, M.D., Ph.D., with the University of Minnesota Medical School, answers questions about who is affected, as well as the diagnoses and treatments available for those with a rare disease.
Q: What is a rare disease? What is an example of a rare disease?
Dr. Lund: The definition of a rare disease is a condition that affects fewer than 200,000 people. There are estimated to be around 7,000 rare diseases, and—currently—it’s estimated the total number of Americans living with a rare disease is between 25 and 30 million people. These numbers demonstrate that even though an individual disease may be considered rare, every family could potentially be touched by one, or at least know someone with one.
I often work with patients with inherited metabolic disorders, like adrenoleukodystrophy (ALD). ALD is a genetic disorder that mainly affects the nervous system and the adrenal glands, the small glands located on top of each kidney. Myelin, the fatty covering that insulates nerves in the brain and spinal cord, deteriorates, reducing the ability of the nerves to relay information to the brain. Children with this genetic disorder, primarily males, experience learning and behavioral problems that usually begin between the ages of 4 and 10 and worsen over time, including difficulty reading, writing, understanding speech and comprehending written material. Additional signs and symptoms include aggressive behavior, vision problems, difficulty swallowing and poor coordination. There is no cure for ALD.
Q: What causes a rare disease and how is it diagnosed?
Dr. Lund: There are many causes of rare diseases. Many are believed to be genetic, which means they are directly caused by changes in genes or chromosomes. In some cases, the genetic changes that cause the disease are passed from one generation to the next. Other times they occur at random.
One in 10 people have a rare disease in Minnesota and half of whom are children. Many families go through an extensive diagnosis that can take years. The child may have some symptoms that may not be specific to their disease, or they may start off by seeing a general pediatrician. This can lead to a child being misdiagnosed at first.
Q: What options are available for treatment of rare diseases when following a diagnosis?
Dr. Lund: While a lot of progress has been made in learning how to diagnose, treat and prevent a variety of rare diseases, there is a lot of work to do because many rare diseases are still without treatments.
At the University of Minnesota Medical School, we did the first successful human bone marrow transplant in the world in 1968 for a patient who had a rare disease known as severe combined immunodeficiency. At that point we set the stage both in bone marrow transplantation and in the treatment of rare diseases. Subsequently, many other patients with rare diseases including immunodeficiency, metabolic storage disease, adrenoleukodystrophy, and a bone disease known as osteopetrosis have been referred to us as patients from all over the world to be evaluated and receive bone marrow transplants in hopes of curing their disease.
Because the university has been a leader in the rare disease world, many are turning to us to lead the way in gene therapy. Whereas traditional drugs minimize symptoms rather than cure the disease, gene therapy has the potential to correct underlying genetic defects, which can lead to a cure rather than simply managing symptoms. Plus, only a single dose of gene therapy is often required for lifelong improvement as opposed to ongoing treatment.
Q: How does gene therapy help individuals with rare diseases and their families?
Dr. Lund: Gene therapy uses genes to treat or prevent disease. Sometimes we can utilize a gene therapy product to add back a normal and functional copy of the gene into the bone marrow stem cells or hematopoietic stem cells. This uses the person’s own cells as a vehicle to deliver the healthy gene. Right now, this is available for just a handful of genes but has been growing by leaps and bounds over the last decade.
Q: What are you doing to advance rare disease research?
Dr. Lund: I spend a lot of time assessing and evaluating patients from all over the world with rare diseases who can be made better through bone marrow transplants. I find the appropriate donors and take patients through the transplant process with assessment follow up thereafter.
My research focuses on determining better biomarkers of the rare disease and their progression. In the laboratory, I study how these diseases work. I can test new drugs and therapies in hopes of finding low-risk solutions with the fewest side effects to help patients with rare diseases.
Dr. Troy Lund is an associate professor in the Department of Pediatrics at the University of Minnesota Medical School, an M Health Pediatric Blood and Marrow Transplant Physician and a Masonic Cancer Center member. He is interested in the use of blood and marrow transplantation (BMT) primarily for patients with inherited metabolic disorders, like adrenoleukodystrophy (ALD) and Hurler syndrome. His goal is not only to save lives but to improve the quality of the lives of kids with rare diseases.
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