A rare disease is generally defined by the incidence rate of a certain disease in a particular region. Therefore, different regions might have different definitions of rare diseases. For example, in Europe, a disease that affects less than 1 in 2,000 people are called a rare disease. In Japan and the United State, rare diseases incidence rate is about 1 in 2,500 and 1 in 1,500 respectively. Sometimes other considerations might be included in defining rare diseases, such as unknown etiology or no effective treatment of diseases. There is no clear definition of rare diseases in Hong Kong, but it is estimated that there are 20,000 rare disease new cases increased each year.
About Neurodegenerative Rare Diseases
Neurodegenerative rare diseases account for about 15% of all the types of rare diseases. Neurodegenerative diseases refer to the progressive degeneration of neuron structure and function. Here are some of the neurodegenerative diseases you might heard of: Parkinson’s diseases, Charcot-Marie-Tooth disease, epilepsy, hereditary spastic paraplegia, spinocerebellar ataxia, spinal muscular atrophy. Other than that, there are hundreds of neurodegenerative diseases that you have not heard of.
The Importance of Genetic Testing for Neurodegenerative Diseases
For patients with early symptoms, genetic testing can find out the genetic variation that causes the disease and assists medical professionals in disease diagnosis. For patients diagnosed at disease early stage, they can be treated as early as possible to control the condition. Since it is hard to regenerate neurons in large numbers, it could be permanent damage for a patient. For patients diagnosed at a later stage of the disease, they could miss the opportunity to effectively control the condition.
Although most of the rare diseases are hard to treat effectively, there are some neurodegenerative diseases can be controlled through gene therapy. Gene therapy is non-invasive, which is safe and effective for long term treatment. It helps slow down the deterioration process so that patients could live a longer life.
Since the occurrence of a rare disease is closely related to genetic inheritance, there is a chance to pass the rare disease gene to the next generation even if the rare disease does not occur. Understanding family medical history and genetic variations help family and life planning.