Rare neurological diseases: a united approach is needed

Abstract

On Dec 2, 2010, a Declaration of Principles on rare neurological disorders of childhood was endorsed by researchers, clinicians, patient advocacy groups, and drug companies during a conference held in the European Parliament in Brussels, Belgium. The initiative, spearheaded by the Brains for Brain international research foundation, aims to advance awareness and knowledge of rare neurological diseases via cross-border collaboration and to enable better diagnosis and management of patients with these diseases. A disease is defined as rare if it has a prevalence of less than 5 per 10 000. However, collectively, rare diseases are surprisingly common, creating a huge health-care and economic burden. There are an estimated 5000–8000 rare diseases, and about 5–8% of the European population is thought to be affected by a rare disease, many of which have neurological manifestations. About 80% of rare diseases have a genetic basis, and onset is often in childhood. Early diagnosis of neurological disorders is the key to halting disease progression. However, diagnosis of rare diseases can be challenging and is often delayed owing to limited knowledge about these conditions among clinicians, as well as difficulties in accessing specialised services. The Declaration of Principles complements current European Union (EU) policy on tackling rare diseases in Europe, which has many varied strands. Current strategies include improving knowledge of rare diseases via the Orphanet project, which is a web portal containing freely available information on more than 5000 rare diseases; strengthening international cooperation by establishing a committee of experts on rare diseases made up of representatives from each member state, patient groups, and pharmaceutical companies; and endorsement of European reference centres that should act as research and knowledge hubs as well as treat patients from other member states. Better recognition and diagnosis of rare disorders is most likely to occur through international collaborations. However, individual countries also need to develop coherent strategies for rare diseases to ensure that patients have access to high-quality care. The EU has recommended that, by the end of 2013, each member state should establish and adopt a national strategy to tackle rare diseases. France led the way, in 2004, by becoming the first country to implement a national plan for rare diseases with dedicated funding. Other nations have since followed suit and have adopted national plans for rare diseases, with dedicated funds, or have strategies currently in preparation; however, many countries, including the UK, Sweden, and Denmark, have not yet made a commitment to developing a national strategy for rare diseases. Progress in developing new treatments for rare diseases requires a strategic partnership between pharmaceutical companies and researchers, and orphan drug legislation provides financial incentives for companies developing drugs for rare diseases. Until recently, research into rare diseases was the realm of smaller biotech companies; however, during the course of 2010, both GlaxoSmithKline and Pfizer—perhaps realising that there is a big market for so-called “niche-buster” drugs—have formed rare disease units. Interest in rare diseases by major pharmaceutical companies is clearly welcome; however, it is essential that they do not charge a premium for any drugs that are shown to be effective. Because of the unmet medical need caused by rare diseases, these disorders deserve attention in their own right. However, learning more about rare diseases could also provide insights or lead to new treatments for common neurological disorders with more complex aetiology. For instance, mutations in the gene encoding the enzyme glucocerebrosidase cause Gaucher disease, a rare inherited lysosomal storage disorder; mutations in the same gene are also a common risk factor predisposing individuals to Parkinson's disease. And mutations in two genes encoding voltage-gated potassium channels cause benign familial neonatal seizures, a rare form of epilepsy. Potassium channels have subsequently been shown to have an important role in more common forms of epilepsy and are among the targets for new antiepileptic drugs. Initiatives such as the Declaration of Principles increase awareness of rare diseases and keep them on the health-care agenda. Although rare diseases are by definition individually rare, collectively they affect millions of people worldwide. A united approach to tackling rare diseases, including pooling of financial and scientific resources, is essential to ensure that patients with rare diseases are given the priority they deserve. ErrataThe Lancet Neurology. Rare neurological diseases: a united approach is needed. Lancet Neurol 2011; 10: 109—In the second paragraph of this Editorial, the first line should read “A disease is defined as rare if it has a prevalence of less than 5 per 10 000.” This correction has been made to the online version as of Feb 21, 2011. Full-Text PDF