54th ENMC International Workshop: PROMM (Proximal Myotonic Myopathies) and Other Proximal Myotonic Syndromes 10–12th October 1997, Naarden, The Netherlands

Proximal myotonic myopathy (PROMM) is a recently delineated, multisystem, autosomal dominant disorder that is similar to but distinct from myotonic dystrophy (DM), and distinct from the non-dystrophic myotonias caused by mutations in the genes for the skeletal muscle chloride and sodium channels. The gene (or genes) responsible for PROMM is unknown. It is possible that patients presently diagnosed as having PROMM may ultimately be members of a heterogeneous group of myotonic diseases having separate gene defects that have led to similar clinical signs and symptoms. However, until a specific diagnostic test is available to help eliminate this potential ambiguity in diagnosis, certain clinical findings and laboratory results need to serve as standard criteria for establishing the diagnosis of PROMM. The major goal for this Workshop was to develop diagnostic criteria, supportive clinical and laboratory findings, and exclusion criteria for classifying patients with PROMM. To achieve this goal 19 participants from nine countries each having extensive experience with PROMM and other myotonic disorders met for 2 days to discuss (1) the clinical spectrum of PROMM, (2) specific laboratory features, (3) molecular genetic studies in PROMM, (4) other related disorders, e.g. proximal myotonic syndromes, (5) criteria for diagnosis, supportive findings, and treatment guidelines.