[Tissue variability of androgen receptor gene in bulbospinal muscular atrophy--comparison of the number of CAG repeats between muscles and peripheral blood leukocytes].

We investigated an expansion of CAG repeats in exon 1 of androgen receptor gene in skeletal muscle tissue obtained from the patients with various neuro-muscular disorders (5 BSMA, 33 patients with amyotrophic lateral sclerosis, 3 patients with spinal progressive muscular atrophy and 2 patients with hereditary motor sensory neuropathy), by polymerase chain reaction (PCR) amplification according to LaSpadas' description. These muscle tissues had been stored at -70 degrees C freezer during 7 years. We also studied the tissue variation of CAG repeats size between muscles and peripheral blood leukocytes in 4 patients with BSMA. And we confirmed the increased number of CAG repeats in all 5 BSMA except for other patients with neurogenic muscular atrophy. In the 4 BSMA patients, we subcloned the PCR products from muscles tissues and peripheral blood leukocytes, and we determined the number of CAG repeats by sequencing. The repeats of them were 43-51, and all BSMA patients showed the same number of CAG repeats in muscles tissues and peripheral blood leukocytes. The CAG repeats fragment of BSMA may be stable region in frozen storage state for 7 years, and we didn't recognized the somatic variation at least between muscles tissues and peripheral blood leukocytes.