Association of spinal and bulbar muscular atrophy with myotonic dystrophy type 1.
A man with spinal and bulbar muscular atrophy (SBMA) had a short (CTG)n expansion in the myotonic dystrophy protein kinase gene as well as (CAG)n expansion in the androgen receptor gene in leukocytes. The patient had the characteristic clinical findings of SBMA, but none of myotonic dystrophy type 1 (DM1). All of his three children (a son and two daughters) had the DM1 phenotype with long (CTG)n expansions. The daughters also had heterozygous long (CAG)n expansions. Postmortem examination of the patient revealed the characteristic pathological changes of SBMA as well as muscle degeneration compatible with DM1. Gene analysis of the organs disclosed unstable long expansions of the (CTG)n repeats, in contrast to the stable (CAG)n expansions. We have assumed that SBMA and DM1 developed independently in our patient, but cannot exclude the possibility that interactive gene effects increased somatic instability.
Jinnai
Kenji
K
Department of Neurology, National Hyogo-Chuo Hospital, 1314 Ohara, Sanda 669-1592, Japan. jinnaike@hyougotyu.hosp.go.jp
Nishimoto
Keisuke
K
Itoh
Kyoko
K
Hashimoto
Kozo
K
Takahashi
Keiichi
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D010244:Bulbar Palsy, Progressive / Q000235:genetics / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000235:genetics / Q000473:pathology*; D014897:Spinal Muscular Atrophies of Childhood / Q000235:genetics / Q000473:pathology*; D018911:Trinucleotide Repeats / Q000235:genetics