title: No relevant excess prevalence of myotonic dystrophy type 2 in patients with suspected fibromyalgia syndrome.
abstract: Myotonic dystrophy type 2 (DM2) is a rare, autosomal dominant, multisystem disorder with proximal weakness, myotonia, pain and cataract as important symptoms. Given the assumed underreporting of DM2 in the Netherlands combined with the predominant role of pain in DM2 as well as in fibromyalgia syndrome (FMS), we hypothesized there will be an excess prevalence of DM2 in patients with (suspected) FMS. Our objective was to determine the prevalence of DM2 in patients with suspected FMS. A prevalence of 2% was considered a relevant excess frequency. Between November 2011 and April 2014, 398 patients with suspected FMS who had been assessed by a rheumatologist participated in this cross-sectional study. 95% of the study population was female, with a mean age of 42 years. The final ICD-9 diagnoses were collected, in 96% the diagnosis was FMS. 92% met the 2010 American College of Rheumatology (ACR) diagnostic criteria for FMS. A questionnaire including neuromuscular symptoms was completed. Creatine kinase was determined, and genetic testing for DM2 was conducted in all patients. DM2 was established in only one patient (0.25%, 95% CI 0.04-1.4%), thus disapproving our hypothesis of a relevant prevalence of 2%. Our results suggest that patients with suspected FMS should not routinely be tested for DM2.
authors.affiliation: Department of Neurology, Canisius Wilhelmina Hospital Nijmegen, P.O. Box 9015, 6500 GS Nijmegen, The Netherlands; Neuromuscular Centre Nijmegen, Department of Neurology, Radboud University Medical Centre, Huispost 935, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: judithvanvliet@hotmail.com.
authors.forename: J
authors.initials: J
authors.lastname: van Vliet
authors.affiliation: Department of Neurology, Canisius Wilhelmina Hospital Nijmegen, P.O. Box 9015, 6500 GS Nijmegen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Verrips
authors.affiliation: Neuromuscular Centre Nijmegen, Department of Neurology, Radboud University Medical Centre, Huispost 935, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: A A
authors.initials: AA
authors.lastname: Tieleman
authors.affiliation: Department of Human Genetics, Radboud University Medical Centre, Huispost 836, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Scheffer
authors.affiliation: Department of Rheumatology, Sint Maartenskliniek, P.O. Box 9011, 6500 GM Nijmegen, The Netherlands.
authors.forename: H A
authors.initials: HA
authors.lastname: Cats
authors.affiliation: Department of Rheumatology, Sint Maartenskliniek, P.O. Box 9011, 6500 GM Nijmegen, The Netherlands.
authors.forename: A A
authors.initials: AA
authors.lastname: den Broeder
authors.affiliation: Neuromuscular Centre Nijmegen, Department of Neurology, Radboud University Medical Centre, Huispost 935, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: B G M
authors.initials: BG
authors.lastname: van Engelen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D005356:Fibromyalgia / Q000150:complications* / Q000201:enzymology / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000150:complications* / Q000201:enzymology / Q000453:epidemiology* / Q000235:genetics; D015995:Prevalence; D016601:RNA-Binding Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: C433227:CNBP protein, human; D016601:RNA-Binding Proteins; D003402:Creatine Kinase
keywords: Fibromyalgia syndrome; Myotonic dystrophy type 2; Pain; Prevalence studies