Eight case reports on sex-hormone profiles in sexually mature male Down syndrome.

Down syndrome (DS) is a congenital disorder usually caused by an extra copy of chromosome 21. Although the number of postpubertal patients with DS is increasing, only limited information is available on their gonadal and sexual development. The aim of this case report was to examine sex-hormone profiles in sexually mature male patients with DS. Eight postpubertal male patients with trisomy 21 (mean age 28 years, range 15-54 years) participated in this study. The serum level of luteinizing hormone and follicle-stimulating hormone was significantly elevated and testosterone was slightly decreased. The testicular volume was smaller in all eight cases than that observed in healthy male subjects. The elevated luteinizing hormone and follicle-stimulating hormone levels, the lower testosterone levels and a smaller testicular volume observed in all eight cases suggest a significant degree of germinal cell hypoplasia in mature male patients with DS.