Rare Disease Day on the 28th February is aimed at raising awareness of the millions of people across the world whose lives are impacted by a rare disease. These are recognised in Europe as a disease that affect less than 1:2000 of the population, but with over 6000 recognised rare diseases this means that in the region of 1:17 people across the world are impact by these types of diseases at some point in their lives.
Whilst some appear later in life, over 50% of these diseases affect children and are often fatal or lead to severe physical or mental disabilities. Some diseases are only just being fully recognised and so have no effective treatments while others are well recognised and understood. However, even in cases where treatments exist, they are often far from ideal and can only control or slow down the progression of the disease, rather than offer any kind of cure.
The treatment for many rare diseases must be administered frequently, such as in the case of haemophilia, which inevitably impacts the patient’s quality of life. Like haemophilia, up to 80% of these diseases are thought to have a genetic component with several through single gene faults. Over the last twenty years scientists have sought to develop approaches for treating these types of diseases at the genetic level, aiming to replace or repair defective genes within the patient’s cells and therefore offering cures for these life threatening illnesses using gene therapy.
Gene therapy offers the potential for a cure rather than a short-term treatment, controlling or managing disease states, and has been applied to a broad range on monogenetic conditions ranging from those affecting infantile development such as Duchene Muscular Dystrophy (DMD) through to those degenerative disease such as Amyotrophic Lateral Sclerosis (ALS). Some of the most impressive results have been seen in ophthalmic conditions such as chlorodermia and retinal pigmentosa for which Spark Therapeutic’s Luxturna was licenced last year. We have also seen truly spectacular reports for the treatment of Type 1 Spinal Muscular Atrophy (SMA) which is a devastating, and ultimately fatal, childhood development condition, and the reporting of ground breaking treatment for epidermolysis bulosa (“butterfly boy”) where a child was treated with a combination of gene therapy and cell engineering.
As our understanding of these rare diseases improves, along with the development of new and innovative medicines and treatment approaches, academic and industrial research groups are finally beginning to bring hope to the many patients impacted by these often neglected disease areas.