Q&A: Rare Disease Day highlights progress, unmet needs in neurology
The NIH is recognizing Rare Disease Day today with virtual panel discussions and other digital programs to raise awareness about the array of rare conditions that affect approximately 30 million Americans, according to its website.
Rare Disease Day is typically on or near the last day of February.
The timeline to diagnosis for a rare disease can take years, and “even after a proper diagnosis, treatment often is unavailable, because only about [5%] of rare diseases have a treatment approved by the FDA,” according to the Rare Disease Day website.
In neurology, rare disorders are a “frequent” consideration for pediatric patients with developmental disabilities or epilepsy. Improvements in the medical community’s knowledge and better tools for genetic testing have enabled clinicians to diagnose some of the rarer disorders in neurology. Other advances include treatment options for these rare diseases; last week, the FDA approved fosdenopterin injection, a first-in-class treatment, for molybdenum cofactor deficiency type A, a rare, genetic, metabolic disorder that typically presents in the first few days of life. In spinal muscular atrophy (SMA), the FDA approved the first gene therapy for the disease and the first oral treatment for the disease within about a year of each other.
Healio Neurology spoke with Tomi Pastinen, MD, PhD, director of the Genomic Medicine Center at Children’s Mercy Kansas City, and Ahmed T. Abdelmoity, MD, FAAP, FAES, director of the division of neurology at Children’s Mercy Kansas City, about the barriers and unmet needs that impact pediatric patients with rare neurological diseases.
Healio Neurology: What barriers to diagnosis or treatment do pediatric patients with rare neurological diseases face?
Pastinen: In rare disease molecular diagnosis, the barriers include access to tertiary care (ie, providers that order molecular tests), insurance reimbursement for genetic testing in some cases and overall low sensitivity for suspected genetic disease (with an estimated 30% yield) in clinical genetic testing. Understanding the contributors for missed diagnosis is complicated by inaccessible tissue, unlike in some other disease (eg, kidney disease) and you are limited in your ability to look for changes directly in the tissue, since you cannot take brain biopsies. Finally, the root cause for some diseases may have occurred in the past (early in the development) and this can hamper studies that aim to understand the mechanisms or to develop targeted therapies.
Abdelmoity: In addition, a number of specific diseases have similar presentations and symptoms that can be shared among many conditions, rendering a financial challenge for obtaining multiple tests to find a specific condition. For example, certain movement disorders and epilepsy syndromes can share some similar features.
Healio Neurology: Are there any research and/or treatments in the pipeline that could affect the management or prognosis of pediatric patients with rare neurological diseases?
Abdelmoity: Regarding diagnosis and treatment of rare neurological disorders, in addition to SMA, there is another condition called aromatic l-amino acid decarboxylase (AADC) deficiency, a serious neurological condition leading to cognitive dysfunction as well as movement disorder significantly affecting quality of life. In recent years, precise genetic and metabolic testing have been instrumental in finding the exact cause of AADC deficiency. Now there is intraputaminal genetic therapy that alters the course of the disease, with significant improvement and high rate of normal development.
- NIH. Rare Disease Day at NIH 2021. Accessed March 1, 2020. Available at: https://ncats.nih.gov/news/events/rdd.