title: Correlation between distribution of muscle weakness, electrophysiological findings and CTG expansion in myotonic dystrophy.
abstract: Myotonic dystrophy type 1 (DM-1) is a multi-system disorder affecting the muscles, brain, cardiovascular system, endocrine system, eyes and skin. Diagnosis is made by clinical, electrodiagnostic and genetic studies. This study aimed to determine the correlation between CTG expansion and distribution of muscle weakness and clinical and electrophysiological findings. Genetically confirmed DM-1 patients presenting to Shariati Hospital between 2005 and 2011 were included in this study. Clinical, electrodiagnostic and genetic testing was performed and the correlation between CTG expansion and distribution of muscle weakness and clinical and electromyographic findings was studied. Thirty-three genetically confirmed DM-1 patients were enrolled. Myotonia, bifacial weakness and distal upper limb weakness were seen in all patients. Diabetes mellitus was found in one patient (3%), cardiac disturbance in eight (24.2%), cataracts in eight (24.2%), hypogonadism in five (15.2%), frontal baldness in 13 (39.4%), temporalis wasting in 14 (42.4%), temporomandibular joint disorder in seven (21.2%) and mental retardation in eight (24.2%). The mean number of CTG repeats, measured by Southern blot, was 8780 (range 500-15,833). A negative correlation was found between CTG expansion and age of onset. Temporalis wasting and mental retardation were positively correlated with CTG expansion. No relationship was found between weakness distribution, electromyographic findings, other systemic features and CTG expansion. In this study of DM-1 in Iran, we found a correlation between CTG expansion and age of onset, temporalis wasting and mental disability. No correlation between CTG expansion and electrodiagnostic and other clinical findings were detected.
authors.affiliation: Department of Neurology, Tehran University of Medical Sciences, Shariati Hospital, North Karegar Street, Tehran 14114, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Khoshbakht
authors.affiliation: Department of Neurology, Tehran University of Medical Sciences, Shariati Hospital, North Karegar Street, Tehran 14114, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Soltanzadeh
authors.affiliation: Department of Neurology, Tehran University of Medical Sciences, Shariati Hospital, North Karegar Street, Tehran 14114, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Zamani
authors.affiliation: Department of Neurology, Tehran University of Medical Sciences, Shariati Hospital, North Karegar Street, Tehran 14114, Iran.
authors.forename: Siyamak
authors.initials: S
authors.lastname: Abdi
authors.affiliation: Department of Neurology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Gharagozli
authors.affiliation: Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors.forename: Kimia
authors.initials: K
authors.lastname: Kahrizi
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Shiraz, Iran.
authors.forename: Rahem
authors.initials: R
authors.lastname: Khoshbakht
authors.affiliation: Department of Neurology, Tehran University of Medical Sciences, Shariati Hospital, North Karegar Street, Tehran 14114, Iran. Electronic address: nafisi@sina.tums.ac.ir.
authors.forename: Shahriar
authors.initials: S
authors.lastname: Nafissi
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000209:etiology*; D009223:Myotonic Dystrophy / Q000150:complications* / Q000235:genetics*; D009431:Neural Conduction / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D013223:Statistics as Topic; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D055815:Young Adult
chemical_list: D017346:Protein Serine-Threonine Kinases
keywords: CTG expansion; Clinical manifestation; Exercise; Myotonic dystrophy