BOX 1-1Examples of Rare Diseases

Dystonia: a group of rare movement disorders that cause involuntary muscle spasms and contractions. Dystonias may be inherited, arise from other conditions (e.g., tumors, infections, stroke), or be of unknown origin. One literature review reported prevalence estimates for primary dystonia (not caused by other medical conditions) that ranged from 2 cases to 50 cases per million for early-onset primary dystonia and from 30 cases to 7,320 cases per million for late-onset primary dystonia (Defazio et al., 2004). Treatment is not curative. Depending on an individual's specific condition, options may include physical, speech, and other nonpharmaceutical therapies; oral medications; injection with botulinum toxin; and surgery, including surgery to implant a deep brain stimulation device.

Glioblastoma multiformae: a rare, highly malignant central nervous system tumor and the most aggressive type of astrocytoma (grade 4). It occurs most often in adults. The Cancer Brain Tumor Registry of the United States estimates its U.S. incidence to be 3 new cases per 100,000 population and estimates that it accounts for approximately 17 percent of all primary brain and central nervous system cancers (CBTRUS, 2010). Surgical removal of as much of the tumor as feasible followed by radiation and chemotherapy is standard treatment but is not curative (NCI, 2009a).

Holocarboxylase synthetase deficiency: an inherited disorder of the metabolism of the vitamin biotin (Wolf, 2008). If not treated, it causes neurological problems (e.g., seizures, movement disorders, intellectual disability, hearing loss), and it may be fatal. It is recommended for inclusion in newborn screening panels. One analysis estimated that newborn screening in 2006 detected 3 cases of the disorder in the United States (Therrell et al., 2008). Early and lifelong treatment with supplemental biotin can prevent symptoms, and those who have developed symptoms may show some improvement with treatment.

Nocardiosis: a rare bacterial infection that most often affects the lungs, the brain, and the skin. People with suppressed immune systems are at higher risk for the disease. The Centers for Disease Control and Prevention estimates that 500 to 1,000 new cases of the disease occur each year and that 10 percent of those with less complicated disease (e.g., uncomplicated pneumonia) may die, but fatality rates are higher for those with more severe disease (CDC, 2008b). Treatment with sulfa drugs generally must continue for several months.

Von Hippel-Lindau syndrome: a complex and variable disease that is caused by defects in a single gene that governs cell growth. It is associated with a range of tumors and cysts, including hemangioblastomas of the brain, spinal cord, and retina; renal cysts; clear cell renal cell carcinoma (the most common cause of premature death); tumors of the adrenal gland; and tumors of the inner ear (Schimke et al., 2009). Based on one study in an English district, it is estimated to affect 1 in 53,000 individuals (Maher et al., 1991). No drug has been approved specifically to treat or cure this disease. Different manifestations of the disease may be treated with surgery, radiation, chemotherapy, and symptom-directed therapies of various types.

From: 1, Introduction

Cover of Rare Diseases and Orphan Products
Rare Diseases and Orphan Products: Accelerating Research and Development.
Institute of Medicine (US) Committee on Accelerating Rare Diseases Research and Orphan Product Development; Field MJ, Boat TF, editors.
Washington (DC): National Academies Press (US); 2010.
Copyright © 2010, National Academy of Sciences.

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