Alpha-fetoprotein (AFP) is a normal fetal glycoprotein (MW = 70,000) initially produced by the yolk sac, and later by the fetal liver. It is found in the fetal circulation throughout gestation, and drops rapidly during the first few weeks of life, reaching normal adult levels by age 1 yr. It is detectable only in trace amounts in normal adult males or nonpregnant females. It is present in amniotic fluid in normal pregnancies, and is detectable in maternal serum starting at ≈ 12–14 weeks gestation, increasing steadily throughout pregnancy until ≈ 32 weeks 1).
The AFP gene is located on the q arm of chromosome 4 (4q25).
Elevated in sacrococcygeal teratoma.
Twelve cases of endodermal sinus tumors were reviewed. There were 10 females and 2 males with a median age at presentation of 3 years. The primary site was sacrococcygeal in 4 patients, vaginal in 3, retroperitoneal in 2, and testicular, ovarian and left chest wall in one each. The diagnosis rested on histopathological examination and elevation of serum alfa feto protein levels (median 46,200 ng/ml). Two patients had Stage I disease, 9 had Stage III and one had Stage IV disease. Patients were managed by surgery and chemotherapy (BVP regime). All patients on BVP (even those lost at later stages), had achieved clinical remission with the first cycle of treatment 2).