Paracentric inversions in man. A French collaborative study. Groupe de Cytogénéticiens Français.

The collection of paracentric inversions ascertained in French cytogenetics laboratories gives a sample of 32 unpublished cases. The carriers seem to have a normal reproductive fitness, without difference between males and females. No cases of aneusomie de recombinaison were found, and it is likely that almost all, and perhaps all cases were ascertained for a cause independent of the inversion. Some chromosomes are too frequently affected: 3, 7 and 14; conversely chromosome 2 was never involved, as in the literature. It remains difficult to know whether paracentric inversions occur at random or not.