Hereditary persistence of {alpha}-fetoprotein: Case report and review of the literature

Persistently elevated -fetoprotein (AFP) levels of 24 to 30µg/ml (normal <10 µg/ml) were found in a 38-year-old healthyman. Subsequently, AFP was found to be elevated in another five out of 13family members within three generations. The pedigree is consistent with anautosomal dominant inheritance pattern. No discernible disease and nofunctional abnormality appears to be associated with this clinically benigndisorder which has been recorded in the literature on four occasions todate. The reported AFP levels in these other cases ranged from 18 to 198µg/ml.Physiologically, AFP is mainly produced in the liver and the yolk sac ofhuman fetuses more than four weeks old, with peak values of up to 4 mg/ml at12 to 16 weeks of gestation. After birth, AFP levels usually fall, withineight to 12 months, to a very low concentration of <10 µg/ml andpersist at low levels throughout life. However, AFP levels can rise abovenormal in both children and adults in distinct conditions and diseases whichwill be discussed.Hereditary persistence of -fetoprotein (HPAFP) should be consideredin both children and adults with unexplained and persistent elevation of AFPe.g., those screened for hepatocellular carcinoma or diagnosed for germ celltumor. It should also be recognized in AFP screening for neural tube defectsor Down's syndrome during pregnancy. Hereditary persistence of AFP can beeasily confirmed by analyzing AFP levels in family members.