Pericentric inversion of chromosome No. 8.

Chromosome studies of an infant with multiple malformations were made by means of the trypsin-Giemsa banding as well as conventional Giemsa staining methods. The propositus showed 46, XY +3, -C, and it was indicated that the abnormal metacentric chromosome was induced by the pericentric inversion of chromosome No. 8, in which chromosomal breakage had occurred most likely at the bands 8p23 and 8q23. The probable formula of the inversion is 46, XY, inv (8) (p23q23). Karyotypic analyses of the parents revealed no abnormalities, and the inversion therefore occurred spontaneously. Clinical features of the porpositus are postulated to be caused by a loss of very small portions of the chromosomal material with the occurrence of the pericentric inversion.