Project Refsum

Presentation of the project

Adult Refsum disease (ARD, MIM#266500) is a rare neurodegenerative disease caused by the accumulation of phytanic acid in tissues. ARD was first described by Sigvald Refsum in 1945 in Norway. The studies of Norwegians families have markedly contributed to disease knowledge. The ARD gene (encoding for phytanoyl-CoA hydroxylase, PAHX) has been identified allowing definitive ARD diagnosis (mutations of other genes can lead to symptoms that mimick Refsum disease) and genetic counseling in affected families. ARD is characterized by marked clinical variation, even within the same family. The diagnosis of ARD is often delayed and made at a late stage when patients fulfil all the classical symptoms. Not all ARD patients present the full spectrum of clinical symptoms and ARD diagnosis is often missed in those cases.

A treatment based on dietary restriction of phytanate and plasmapheresis is available, both strategies aiming at reducing the levels of phytanate in tissues. The benefits of these two therapeutic approaches are however not yet clearly demonstrated.

A European project (RDDPT contract) has been funded by EU. This project aims to characterize in depth the clinical and biochemical consequences of ARD and study the genotype-phenotype correlations. In an attempt to propose preventive therapeutic interventions before lesions become irreversible, this study will allow to identify ARD patients who are at risk to develop specific complications of the disease. This study aims also to retrospectively evaluate the effects of dietary and plasmapheresis approaches on the natural evolution of ARD disease. Lastly, this study will allow to determine the real incidence and prevalence of ARD in each european country.

The european coordinator of this clinical project is Pr. Ola Skjeldal (Rikshospitalet, Oslo, Norway; ), assisted by Dr. Morten Horn (Department of Neurology, Ullevål Universitetssykehus, Oslo, Norway; ) and Dr. Chantal Tallaksen (Ullevål Universitetssykehus, Oslo, Norway;).

The french coordinator is Pr. P. Aubourg ((Hôpital Saint-Vincent de Paul, Paris, France).

Objectives and expected achievements

Describe the different clinical aspects, severity grade, pre-clinical and reversible symptoms of ARD to increase the efficacy of preventive therapeutic interventions.

Methods

• - set-up of a network regrouping as many as possible physicians taking care of ARD patients in Europe (the number of ARD patients is estimated to be 200 in Europe, but the real number is likely underestimated), with possible extension to other non-european countries.
• - Standardized evaluation of clinical symptoms (phenotype).
• - Biochemical and genetic (PAHX gene) studies.
• - Evaluate the prevalence of ARD among patients with undiagnosed retinitis pigmentosa.

Ethical aspects will be considered in relation to the conventions of the Council of Europe on human rights and biomedicine, as well as the legal regulations in each european country to preserve information confidentiality and rights of the patients.

Project planning

2004-2005 : set-up of european network of physicians taking in charge ARD patients.

2005-2008 : study the clinical and biochemical phenotypes, genotype-phenotype correlations in ARD

Importance of the project

Important biochemical and genetic progresses has been made in the last few years in Refsum disease. One can therefore hope to improve markedly the quality of patient life on the basis of new therapeutic interventions. Towards this goal, it is essential to know the natural evolution of the disease. This project will involve tight collaborations between clinicians (neurologists, paeditricians in particular), biochemists, molecular biologists and geneticians.

The success of this project relies entirely on the willingness of physicians that take care of ARD patients to participate actively to this project and share informations.

Contact in France

If you are affected by Refsum disease and are willing to participate to this project or if you want to have additional informations,

If as a physician you take care of a patient with Refsum disease and want to participate to this project or have additional informations,

you can contact :

Pr. Patrick Aubourg
Hôpital Saint-Vincent de Paul
82 avenue Denfert-Rochereau
75014 Paris France
tel: 33 1 4048 8164 (secretary)
fax: 33 1 4048 8340
e-mail: