Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

FECHS
60371
iron. It occurs normally in almost all tissues of the body but especially in hepatocytes and
reticuloendothelial cells, where it serves as an iron reserve. Ferritin is also present in the serum in minute
amounts, where it appears to reflect iron stores in normal individuals. Ferritin plays a significant role in
the absorption, storage, and release of iron. As the storage form of iron, ferritin remains in the body
tissues until it is needed for erythropoiesis. When needed, the iron molecules are released from the
apoferritin shell and bind to transferrin, the circulating plasma protein that transports iron to the
erythropoietic cells. A low serum ferritin value is thought to be the best laboratory indicator of iron
depletion. Virtually all patients with low serum iron and low ferritin have iron deficiency. Serum ferritin
is clinically useful in distinguishing between iron-deficiency anemia (serum ferritin levels diminished)
and "anemia of chronic disease" (serum ferritin levels usually normal or elevated). Serum ferritin is a
good screening test in separating erythrocyte microcytosis due to iron deficiency (low values) from
microcytosis related to thalassemia minor (normal or high values). An iron-depletion state with a
decreased serum ferritin value is quite common among menstruating and reproductively active females
and in children. Ferritin is an acute phase reactant. A normal serum ferritin value, therefore, cannot be
used to exclude iron deficiency if a hepatic, malignant, or inflammatory condition is present. A high
serum ferritin value is seen in hemochromatosis and other iron-overload states, as well as acute hepatitis,
Gaucher disease, malignancies, and chronic inflammatory disorders.
Useful For: Diagnosing iron deficiency and iron-overload conditions
Interpretation: Hereditary hemochromatosis or other iron-overload states, acute hepatitis, and
Gaucher disease are associated with very high serum ferritin levels. Slight-to-moderate elevation occurs
in many malignancies and in chronic inflammatory disorders. Iron deficiency (uncomplicated) Males:
307 mcg/L In
hemochromatosis, ferritin is often >1,000 mcg/L For more information about hereditary
hemochromatosis testing, see Hereditary Hemochromatosis Algorithm in Special Instructions.
Reference Values:
Males: 24-336 mcg/L
Females: 11-307 mcg/L
Clinical References: 1. Fairbanks VF, Beutler E: Iron Metabolism. In Williams Hematology.
Edited by E Beutler, MA Lichtman, BS Coller, et al. New York. McGraw-Hill Book Company, 2001,
pp 295-304 2. Fairbanks VF, Brandhagen DJ: Disorders of iron storage and transport. In Williams
Hematology. Edited by E Beutler, MA Lichtman, BS Coller, et al. New York. McGraw-Hill Book
Company, 2001, pp 489-502 3. Brugnara C: Iron deficiency and erythropoiesis: new diagnostic
approaches. Clin Chem 2003 Oct;49(10):1573-1578 4. Schilsky ML, Fink S: Inherited metabolic liver
disease. Curr Opin Gastroenterol 2006 May;22(3):21
Ferrochelatase (FECH) Gene, Full Gene Analysis
Clinical Information: Erythropoietic protoporphyria (EPP) is an inherited disorder of porphyrin
metabolism whose clinical manifestations include painful photodermatosis without blisters and liver
disease. The disorder results from decreased activity of the enzyme ferrochelatase (FECH). FECH is the
last of 8 enzymes acting sequentially in the heme biosynthetic pathway and is encoded by the FECH
gene located on chromosome 18. The skin symptoms in EPP include immediate painful
photosensitivity, usually beginning in early infancy upon sun exposure. Repeated photosensitivity
episodes result in skin thickening and areas of hyperkeratosis. This is typically noted on areas where sun
exposure is most common, such as the dorsa of the hands and on the face. A small number of patients
with EPP develop liver complications. Hepatic disease in EPP may include cholelithiasis and chronic
liver disease progressing to rapid acute liver failure. Biochemically, EPP is characterized by elevated
protoporphyrin levels in red blood cells, which fluorescence under Woodâ€s light due to the
accumulation of free protoporphyrin IX. Protoporphyrin elevations may also be found in plasma and
stool, but not in all patients. Urine protoporphyrin levels are usually normal unless there is liver
involvement. Studies have also suggested that a reduction in activity of ferrochelatase to