Increased frequency of induced sister chromatid exchanges in kwashiorkor.

The study included 16 infants with advanced manifestations of kwashiorkor and 16 unrelated age-matched normals as controls. Whole blood samples, at room temperature, were exposed to gamma-rays in increasing dosages. Lymphocytes were cultured; phytohaemagglutinin and bromodeoxyuridine (10 microM) were added, at initiation of culture, and harvesting was performed after 64 to 68 h. Slides were coded and sister chromatid exchanges (SCE) counted. In controls, no significant increase in the frequency of SCE was found. For kwashiorkor infants the SCE frequencies showed significant increase as irradiation dosages rose. It is concluded that the changes observed are probably due to alteration in: the cell cycle length; activities of enzymes responsible for DNA repair; DNA growing points; and protection of cells from chromosome breakage.