Cross-sectional Study of Patients With Renal or Craniocervical Fibromuscular Dysplasia

ARCADIA is a national registry designed to document phenotypic and genetic traits in patients with renal and/or cervical artery fibromuscular dysplasia (FMD). FMD is a group of arterial diseases that most commonly involve renal and carotid arteries. Patients with FMD may present with renovascular hypertension and/or with cerebrovascular symptoms. Angiographic classification includes the multifocal type and the focal type. FMD may affect one or more vascular beds and progress to more severe stenosis and to renal or cerebrovascular complications. FMD may be familial (OMIM #135580). Our main objective is to create a FMD registry that will collect standardized information from all consenting patients diagnosed with the condition in 16 participating centers. This registry, along with a collection of leukocyte DNA, will constitute a resource for further clinical research on FMD. The first application will be the assessment of the frequency of multi-site FMD, i.e. the frequency of cervical artery FMD in patients presenting with renal artery FMD and vice-versa. The second application will be a case-control study to identify susceptibility genes for FMD. Patients are eligible in the registry if: (a) they have renal or cervical artery FMD with either multifocal or focal lesions at CT-angiography, MR-angiography, or intra-arterial angiography; (b) they give informed consent to leukocyte DNA analysis and to the collection of bioclinical and morphologic information. Phenotypic assessment will be performed in accordance with current recommendations and best clinical practice. Given the multicenter nature of the study and the recruitment capacity of each centre, enrollment of 500 FMD cases is expected over 5 years. This number will 1) allow an accurate estimation of the frequency of multi-site FMD: when the sample size is 500, a two-sided 95% confidence interval will extend 0.035 from the observed proportion for an expected proportion of 0.20 based on a previous report and fro