title: Epidemiological and genetic studies of myotonic dystrophy type 1 in Taiwan.
abstract: To investigate the prevalence and genetic characteristics of myotonic dystrophy type 1 (DM1) in Taiwan, DM-suspected patients and their families identified during the period of 1990-2001 had their clinical records reevaluated and the CTG repeat sizes at the DM1 locus examined. A total of 96 subjects belonging to 26 families were identified as DM1 patients, which gave a minimal disease prevalence of 0.46/100,000 inhabitants. Clinical anticipation was frequently observed in affected families, even in some parent-child pairs with transmission contraction of the CTG repeat size. The inverse correlation between age at onset and CTG repeat length was significant only in patients with small expansions. In addition, a DM1 carrier with a childhood-onset son was found to have CTG length heterogeneity in the range of 40-50, indicating that premutation alleles could be unstable during gametogenesis as well as in somatic tissues. Our data demonstrated that DM1 is a rare disease in Taiwan and showed that transmission contraction of repeat size is more likely to occur in alleles with large repeats.
authors.affiliation: Department of Life Sciences, Chung Shan Medical University, No. 110 Sec. 1 Chien-Kuo North Road, Taichung, Taiwan 402, ROC. kmh@csmu.edu.tw
authors.forename: K M
authors.initials: KM
authors.lastname: Hsiao
authors.forename: S S
authors.initials: SS
authors.lastname: Chen
authors.forename: S Y
authors.initials: SY
authors.lastname: Li
authors.forename: S Y
authors.initials: SY
authors.lastname: Chiang
authors.forename: H M
authors.initials: HM
authors.lastname: Lin
authors.forename: H
authors.initials: H
authors.lastname: Pan
authors.forename: C C
authors.initials: CC
authors.lastname: Huang
authors.forename: H C
authors.initials: HC
authors.lastname: Kuo
authors.forename: S B
authors.initials: SB
authors.lastname: Jou
authors.forename: C C
authors.initials: CC
authors.lastname: Su
authors.forename: L S
authors.initials: LS
authors.lastname: Ro
authors.forename: C S
authors.initials: CS
authors.lastname: Liu
authors.forename: M C
authors.initials: MC
authors.lastname: Lo
authors.forename: C M
authors.initials: CM
authors.lastname: Chen
authors.forename: C C
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000097:blood / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000453:epidemiology* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013624:Taiwan / Q000453:epidemiology; D018911:Trinucleotide Repeats / Q000235:genetics
chemical_list: D004247:DNA