Prevalence of Fabry's Disease in a Population of Patients With Chronic Pain
Condition: Fabry's Disease; Chronic Pain
MeSH terms: Fabry Disease; Chronic Pain
Study type: Interventional

Summary: 
      Fabry disease is a rare inherited metabolic disorder that predominantly affects heart,
      kidneys and nervous system. Fabry disease has been searched in series of patients presenting
      different isolated signs caused by the affection of one of these organs. Acroparesthesias and
      chronic crises of pain of different origins are reported in the large majority of patients
      during the progression of the disease. Moreover, this signs are frequently inaugurating the
      disease. The investigators have previously performed a preliminary single-center study which
      permitted to identify one female patient with Fabry disease in a series of 147 consecutive
      patients with chronic pain tested. The investigators now propose to confirm the results of
      our preliminary study. The investigators plan to evaluate the prevalence of Fabry disease in
      a series of 1000 patients suffering from chronic pains of undetermined aetiology and
      consecutively recruited.
    

Detailed description: 
      Fabry disease (FD) is a rare X-linked multisytemic lysosomal disorder caused by
      alpha-galactosidase deficiency. Globotriaosylcéramide (Gb3) deposits are observed in almost
      all tissues examined. Signs of the disease appear earlier and are more severe in affected
      males than in females. Myocardiopathy, renal failure and neurological signs including chronic
      pain and peripheral neuropathies are the most frequent signs. The availability of two
      enzymatic replacement therapies now provides a specific and effective treatment for patients.
      The prevalence of FD is estimated between 1/40,000 and 1/117,000. The frequency of Fabry
      disease has previously been estimated in several series of patients presenting one single
      sign, ie renal failure, hypertrophic myocardiopathy and early onset stroke. However, no data
      are available about the prevalence of FD in populations of patients suffering from chronic
      pains of unknown origin.

      The diagnosis of FD will be performed by standard procedures following international
      recommendations. These require the search for a deficiency of alphagalactosidase A activity
      on leucocytes in males and genetic analysis of the GLA gene in females (Germain et al. 2010).

      The patients in whom the diagnosis of FD is established during this study, will be call in
      for an additional visit in the Investigating Centre in order to confirm the diagnosis and
      propose suitable assessment and care.
    

Intervention name(s): Diagnosis of Fabry disease
Intervention type(s): Genetic
Intervention description(s): The diagnosis of Fabry disease necessitates biochemical enzymatic measures of alphagalactosidase A activity in males, and genetic analysis using direct sequencing of GLA in females.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Prevalence Study; Fabry's disease; Chronic pain