Heteromorphisms of pericentromeric heterochromatin of chromosome 19

The pericentromeric heterochromatin of chromosome 19 exhibits considerable variation even by the G-banding technique. Nevertheless, the C-banding technique has been universally employed to investigate pericentromeric hetromorphisms. We demonstrate that optimal expression of the pericentromeric region can be achieved by using the AluI/G technique. The pericentromeric heterochromatin of chromosome 19 is classified into four classes (I-IV). Fifty normal individuals were evaluated and the incidence of types I-IV were 26%, 17%, 51%, and 6%, respectively. No consistent relationship was observed between the types of heterochromatin identified by the AluI/G technique when compared with the other routinely used procedures.