title: Strong correlation between the number of CAG repeats in androgen receptor genes and the clinical onset of features of spinal and bulbar muscular atrophy.
abstract: X-linked spinal and bulbar muscular atrophy (SBMA), a motor neuron disease associated with androgen insensitivity, is caused by androgen receptor gene mutations with an increased number of tandem CAG repeats in exon 1. We investigated the increased number of CAG repeats in androgen receptor genes of 19 SBMA patients and found that this correlated strongly with the age at onset of muscle weakness. Thus, SBMA is the first genetic disease in which a strong correlation between the degree of genetic abnormality (number of CAG tandem repeats) and clinical phenotypic expression is demonstrable. The results further indicate that androgen gene mutation is directly involved in the degeneration of motor neurons.
authors.affiliation: Department of Neurology, Nishi-Ojiya Byoin National Sanatorium, Niigata, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Igarashi
authors.forename: Y
authors.initials: Y
authors.lastname: Tanno
authors.forename: O
authors.initials: O
authors.lastname: Onodera
authors.forename: M
authors.initials: M
authors.lastname: Yamazaki
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: A
authors.initials: A
authors.lastname: Ishikawa
authors.forename: N
authors.initials: N
authors.lastname: Miyatani
authors.forename: M
authors.initials: M
authors.lastname: Nagashima
authors.forename: Y
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: K
authors.initials: K
authors.lastname: Sahashi
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009134:Muscular Atrophy, Spinal / Q000235:genetics*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011944:Receptors, Androgen / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D011944:Receptors, Androgen