Information for clinicians

7 Clinical investigation and management

7a Evaluations at initial diagnosis

• Ophthalmologic examination
• Neurologic examination
• Audiologic evaluation including pure tone audiometry and possibly otoacoustic emission testing and auditory brainstem evoked response (ABR) testing if hearing difficulties are suspected but not identified on pure tone audiometry [Bamiou et al 2003].
• Cardiac evaluation including electrocardiography (ECG) and cardiac ultrasound examination.

7b Treatment of manifestations

[More details coming soon]

• Retinitis pigmentosa [details to follow]
• Polyneuropathy [details to follow]
• Hearing loss [details to follow]
• Ataxia [details to follow]
• Ichthyosis needs lifelong treatment with hydrating creams
• Cardiac arrhythmias and cardiomyopathy need regular care by a cardiologist in order to treat signs and symptoms properly with anti-arrhythmic and cardiogenic supportive drugs

7c Prevention of primary manifestations

No curative therapy currently exists for adult Refsum's disease.

By restricting dietary intake of phytanic acid or eliminating phytanic acid by plasmapheresis or lipid apheresis [Gibberd et al 1979, Moser et al 1980, Gutsche et al 1996] plasma phytanic acid concentrations can be reduced by 50-70%, typically to about 100 to 300 µmol/L. This reduction in plasma phytanic acid concentration successfully resolves symptoms of ichthyosis, sensory neuropathy, and ataxia in approximately that order. However, it is uncertain whether treatment affects the progression of the retinitis pigmentosa, anosmia and deafness [Gibberd & Wierzbicki 2000].

Furthermore, a high-calorie diet is necessary to avoid mobilization of stored lipid, including-phytanic acid, into the plasma. Postoperative care requires parenteral nutrition.

7c(i) Agents/circumstances to avoid

All food products originating from ruminants, i.e. meat, butter, and milk. (See information for patients - 'Diet for treatment of adult Refsum's disease'.)

Fasting that mobilizes stored lipids, including phytanic acid, into the plasma. (See information for patients - 'Illness - taking extra care'.)

7d Therapies under investigation

At present, the potential of enzyme replacement therapy (ERT) similar to that for lysosomal storage diseases (e.g. Hurler syndrome (MPS I), Fabry disease and Gaucher disease) is under investigation. This may eventually replace dietary restrictions and plasma- or lipapheresis.

In the long run, gene therapy may be the treatment of choice, but many issues need to be resolved before this can be applied.

Next: Genetic counselling

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Page last updated 26 June 2006