An Iron Overload Disorder - what are the tests?
| 1. | Transferrin Saturation (TS) TS is the ratio of two simple blood tests, which indicates iron accumulation. Serum iron is divided by total iron binding capacity (TIBC) to give the TS percentage. The test should be performed after an overnight fast. Normal average is 30% (slightly higher in men than women). If on two occasions this is over 55% in men or 50% in women, GH is very likely and one should proceed to measure: |
| 2. | Serum Ferritin This indicates the amount of iron stored in the body. Levels significantly over 300µg/l [micrograms per litre] in men and 200µg/l in women are further evidence of GH. It should be realised that in the early stages of iron accumulation, serum ferritin may be within the normal range. Raised TS with a normal serum ferritin level does not rule out a diagnosis of GH. |
| 3. | Gene Test A simple blood test for the HFE gene mutation is positive in over 90% of those affected. It will identify family members at risk of loading iron. |
| 4. | Liver Biopsy A small sample of the liver is removed using a biopsy needle, which shows whether tissue damage such as cirrhosis is present. It is recommended when the serum ferritin reading is over 1000µg/l, there is evidence of abnormal liver function, or the HFE test is negative. |