Polymorphism of chromosome 9 in 600 Greek subjects.

The morphologic variations of C-band heterochromatin of chromosome 9 were studied in 600 Greek subjects referred for cytogenetic investigation. There was great variability in the location and length of the heterochromatic bands. The location and length of the heterochromatic band were equal in 177 individuals and unequal in 423. Twenty-five subjects (4%) carried a pericentric inversion on one of the homologs, and 12 individuals (2%) had an extremely elongated C-band in one homolog 9. Our findings are compared with those reported in the literature, and the ethnic variation is discussed and evaluated.