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 (Lidove et al. 2007).

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.

Inclusion Criteria:

• patients of both sex
• aged from 6 to 65
• with chronic pains of unknown aetiology including:
• acroparesthesias
• and/or pain crises evolving more than 3 months
• continued neuropathic evolving more than 3 months
• and/or multiple pains evolving more than 3 months
• and/or recurrent abdominal crises of pain who come for a clinical visit in the Centre Douleurs Chroniques in the CHU of Bordeaux.

Exclusion Criteria:

• chronic pain of known cause