INDIVIDUAL VARIABILITY IN HOMOCYSTEINE RESPONSE TO FOLATE-DEPLETION -AN UNUSUAL CASE

Research within the past decade has shown that even moderately elevate d plasma homocysteine concentrations are associated with increased ris k of vascular disease. A variety of genetic and nutritional factors ca n affect homocysteine concentrations, with folate nutriture being one of the most influential. Plasma homocysteine responses of healthy adul ts to folate depletion and repletion vary substantially, even when man y nutritional and lifestyle factors are normalized in a metabolic unit . The case of a woman with a highly exaggerated homocysteine response to moderate folate depletion is presented. A variety of possible facto rs relating to homocysteine metabolism are discussed, yet no convincin g explanation for the unusual pattern is apparent. The case demonstrat es that the homocysteine response to folate can be highly variable bet ween individuals, and suggests that further research on the genetic de terminants of the human folate requirement is warranted.