Paracentric inversion of a human chromosome 7.

In the course of chromosome studies of atomic bomb survivors in Hiroshima using the trypsin-G-banding and Q-banding methods, a 40-year-old male was found to have an abnormal banding pattern in the long arm of a chromosome 7, although no such abnormality was detected by ordinary staining method. Since all other chromosomes apparently had normal banding patterns, the abnormality was determined to be a paracentric inversion of a chromosome 7, which is described as 46, XY, inv (7) (q22q31). This is the first demonstration of a possible paracentric inversion in man.