Fabry disease 'The New Great Imposter': results of the French Observatoire in Internal Medicine Departments (FIMeD).

Fabry disease (FD) is an X-linked lysosomal storage disorder due to α-galactosidase A deficiency. It is associated with a broad range of clinical symptoms, resulting in frequent misdiagnosis and diagnostic delay, which may impact on patient outcomes. This retrospective observational study of 58 FD patients referred to 10 internal medicine departments in France aimed to review differential diagnoses received prior to diagnosis and examines diagnostic delay. The average age at the time of diagnosis was 27.6 years (range: 10-60) and 42.2 years (range: 9-77) among the 23 males and 35 females analyzed, respectively. Most common symptoms that led to FD diagnosis were family history of FD (12 males and 27 females), followed by pain in extremities (10 males and 5 females), and angiokeratoma (8 males and 4 females). Eighteen patients had received alternative diagnoses prior to FD diagnosis, including a female patient with four previous diagnoses. Four case reports are presented, which illustrate the diagnostic 'odyssey' and delayed diagnosis often experienced by patients. Clinicians should consider a diagnosis of FD when presented with a wide range of symptoms, thus helping to shorten the diagnostic delay and facilitating early therapy with enzyme replacement therapy to improve patient outcomes.