Polymorphism of Human Constitutive Heterochromatin

Science  12 Nov 1971:
Vol. 174, Issue 4010, pp. 702-704
DOI: 10.1126/science.174.4010.702


Genetic polymorphism has been demonstrated in man for many characteristics including blood groups, serum proteins, tissue enzymes, and hemoglobins. A class of chromosomal polymorphism involving constitutive heterochromatin has now been found. Through the use of a special technique that permits visualization of heterochromatin, seven heterochromatin variants have been found among four individuals. These results suggest a very high frequency of variability of heterochromatin in the population.