title: Survival and CTG repeat expansion in adults with myotonic dystrophy type 1.
abstract: BACKGROUND
  An association is observed between the severity of myotonic dystrophy type 1 (DM1) and the genetic abnormality of cytosine-thymine-guanine (CTG) repeat expansion. It is unknown whether an association exists between survival and CTG repeat expansion.
  
  
  METHODS
  In an adult 406-patient DM1 cohort, the phenotype, including survival age, was evaluated in relation to CTG repeat expansion.
  
  
  RESULTS
  At study entry, age was 42 ± 12 (range 18-78) years, with a CTG repeat length of 629 ± 386 (range 54-1965). An inverse correlation was observed between CTG repeat length and the age at onset and younger DM1 phenotype. Over a follow-up of 9.2 ± 3.1 years, 118 (29.1%) patients died, including 60 of neuromuscular respiratory failure, 41 of cardiac causes, and 17 of non-neuromuscular, non-cardiac causes. There was an inverse relationship between all-cause survival and CTG length (relative risk 5.4 per log repeat, 95% confidence interval 2.9-10.2, P < 0.001).
  
  
  CONCLUSIONS
  The data demonstrate a genotype-mortality association in DM1.
authors.affiliation: Department of Medicine, Division Cardiology, Krannert Institute of Cardiology, Indiana University, 1800 North Capitol, Room E300C, Indianapolis, Indiana 46202, USA. wgroh@iupui.edu
authors.forename: William J
authors.initials: WJ
authors.lastname: Groh
authors.forename: Miriam R
authors.initials: MR
authors.lastname: Groh
authors.forename: Changyu
authors.initials: C
authors.lastname: Shen
authors.forename: Darren G
authors.initials: DG
authors.lastname: Monckton
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Bodkin
authors.forename: Robert M
authors.initials: RM
authors.lastname: Pascuzzi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003596:Cytosine / Q000737:chemistry; D005260:Female; D005500:Follow-Up Studies; D006147:Guanine / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000235:genetics / Q000378:metabolism / Q000401:mortality; D015996:Survival Rate / Q000639:trends; D013941:Thymine / Q000737:chemistry; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D055815:Young Adult
chemical_list: D006147:Guanine; D003596:Cytosine; D013941:Thymine