Abstract
Background—Serum ferritin is normally a marker of iron overload. Ferritin genes are sited at chromosomes 19 and 11. Regulation of ferritin synthesis involves an interaction between an iron regulatory protein (IRP) and part of the ferritin mRNA designated the iron regulatory element (IRE). A disorder of ferritin synthesis resulting in hyperferritinaemia in the absence of iron overload has been described recently. Patients and methods—Hyperferriti- naemia in the absence of iron overload was detected in a patient who was investigated for possible haemochromatosis. Serum iron, transferrin saturation, and ferritin concentration were studied in 11 members of this patient's family from three generations. Eight members had DNA samples analysed by direct cycle sequencing of the 5' untranslated region of the L ferritin gene. Results—Six of the family members studied had serum ferritin concentrations greater than 900 µg/l. However, serum iron and transferrin saturation were normal in these subjects who all had evidence of cataracts. Three affected family members who had genetic studies of the L ferritin gene on chromosome 19 had an A to G point mutation which was not found in unaffected members. Conclusions—There was complete concordance between a mutated IRE, cataracts, and hyperferritinaemia in three generations of this family. This family study confirms the finding that hereditary hyperferritinaemia in the absence of iron overload is an autosomal dominant inherited disorder.
Keywords: ferritin; hyperferritinaemia; hereditary haemochromatosis; cataract; iron overload
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Figure 1 .
: Family tree of the patients with hyperferritinaemia. Solid symbols indicate those with ferritin in excess of 900 µg/ml; symbols with crosses indicate ferritin concentrations within the normal range; clear symbols indicate spouses in whom the ferritin concentrations have not been measured.
Figure 2 .
: Cataract in patient I2.