男子不妊症における染色体異常頻度と染色体異常症例の臨床的検討

Abstract

1985年1月からの6年4ヵ月間に男子不妊症1, 001例の末梢血染色体検査を行った.1)無精子症154例では正常変異を除く染色体異常の頻度は10.4%で, Klinefelter症候群が7.8%と多数を占めた.精子濃度2, 000万/ml以下の乏精子症326例では, 染色体異常は4.6%に認められ, 常染色体転座が3.1%と多数を占めた.無および乏精子症では, 精子数正常群に比べて染色体異常の頻度は有意に高く, 染色体検査の適応と考えられる.2) Klinefelter症候群12例はすべて無精子症であったが, 血清テストステロン値は正常の症例が多く, 男性ホルモン補充療法を行った症例はなかった.3)染色体構造異常18例のうち, 精巣生検により5例でspermatogenic arrestが認められ, 染色体構造異常が減数分裂を障害していることが示唆された

A chromosomal survey using the G-banding technique was performed on 1, 001 subfertile males examined at Kyoto University Hospital between January, 1985 and April, 1991. Thirty-six of them had major chromosome anomalies (3.6%). The incidence of major anomalies for the 154 azoospermia patients, 326 oligozoospermia patients with a sperm density of less than 20 x 10(6)/ml, and 521 patients with normal sperm density was 10.4, 4.6, and 1.0%, respectively. The major anomalies found in azoospermic patients were associated with the sex chromosome, whereas autosomal anomalies were found in patients with oligozoospermia. The incidence of anomalies for patients with azoo- or oligozoospermia was significantly higher than that for patients with normal sperm density (p = 0.000003). All of the 12 patients with Klinefelter syndrome were azoospermic. However, the serum testosterone levels were within normal range in 10 of these patients. Testicular biopsies showed spermatogenic arrest in 5 of the 12 azoo- or oligozoospermic patients with structural chromosomal anomalies. Except for one patient, treatments such as varicocelectomy or medication were not effective in the patients with structural chromosomal anomalies. Chromosome studies are important in the evaluation of subfertile male patients with sperm densities less than 20 x 10(6)/ml. Disorders of the spermatogenic process may be directly related structural chromosomal anomalies in some of the patients.