Analysis of Familial Tendencies in Transferrin Saturation in a Korean Population

Despite the high transferrin saturation (TS) level in Koreans, the p.Cys282Tyr and p.His63Asp mutations are markedly less frequent than in Caucasians. We aimed to determine TS levels and their familial tendencies in a Korean population using nationwide data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1 2010).

A total of 4904 subjects without a history of hepatitis B and C virus infection, or liver cirrhosis, and who were negative for anemia and hepatitis B antigen were enrolled. A familial tendency analysis was performed in 260 families. Parents were grouped into four quartiles based on their TS levels. Offspring were categorized according to the mean parental TS four quartile scores (1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0). A familial tendency was evaluated by comparing the mean TS of offspring in seven parental groups.

The mean TS was 39.3 ± 15.6% for Korean males and 33.2 ± 12.9% for Korean females, and both were significantly higher than those of Caucasians reported in the HEIRS study (30.6 ± 11.0% for male, 25.6 ± 10.6% for female, P < 0.001). The 260 families showed statistically significant familial tendencies of TS values (P < 0.001). The mean TS of offspring in parental group 1.0, 1.5, 2.0, and 2.5 showed a lower value than that in higher group 3.0, 3.5, and 4.0. In contrast, there were no significant differences in age, daily dietary iron intake, and AST or ALT value among seven groups.

These findings suggest unidentified genetic variations on high TS in Koreans beyond the p.Cys282Tyr and p.His63Asp mutations commonly identified in Caucasians.