title: Machado-Joseph disease/SCA3 and myotonic dystrophy type 1 in a single patient.
abstract: We report here, for the first time, the case of a 41-year-old man with both Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3) and myotonic dystrophy type 1. The patient noted dysarthria at 14 years of age and unsteady gait at 30 years of age. Similar sized expansions of the CAG trinucleotide repeats in one allele of the ataxin-3 (ATXN3) gene were found in both the patient and his father, although in the other allele the length of the CAG repeats was shorter in the father compared with the patient. In the dystrophia myotonica protein kinase (DMPK) gene the CTG repeats were much more expanded in the patient compared with his father. Thus it is possible that, in the farther, the short CAG repeat in the non-expanded ATXN3 allele delayed the onset of cerebellar symptoms, and/or that the expanded CTG repeat in the DMPK gene in the patient accelerated the pathogenesis of MJD/SCA3.
authors.affiliation: Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan. shiroh46@med.kurume-u.ac.jp
authors.forename: Shiroh
authors.initials: S
authors.lastname: Miura
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Ohyagi
authors.forename: Taro
authors.initials: T
authors.lastname: Miike
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Noda
authors.forename: Kyoko
authors.initials: K
authors.lastname: Motomura
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ayabe
authors.forename: Hisamichi
authors.initials: H
authors.lastname: Aizawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Taniwaki
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy; D001921:Brain / Q000473:pathology; D004401:Dysarthria / Q000209:etiology; D018737:Hand Strength; D006801:Humans; D017827:Machado-Joseph Disease / Q000150:complications* / Q000235:genetics* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D018908:Muscle Weakness; D009223:Myotonic Dystrophy / Q000150:complications* / Q000235:genetics* / Q000473:pathology; D009460:Neurologic Examination; D018911:Trinucleotide Repeats