Fetal gonadal histology in XXXXY, XYY and XXX syndromes.

During a 3-year period in which 1500 amniotic fluid samples were studied, six cases of sex chromosome abnoramlity were detected antenatally: two with XXX, three with XYY and one with XXXXY sex chromosome constitution. After careful counselling, the parents in each case chose termination of the pregnancy, which was performed at the 20th week of gestation. All fetuses appeared normal and showed no gross malformations. Histologic investigation of the gonads of the XXXXY, one XYY and one XXX fetus showed a normal overall picture. The number of spermatogonia in the seminiferous tubules of the XXXXY male fetus was markedly reduced and the testes of the XYY fetus also contained less spermatogonia than testes from control fetuses.