raised ferritin levels are not uncommon as there are many causes, and most cases are NOT due to hereditary haemochromatosis
patients with persistently raised ferritin levels without explanation should be considered for genetic testing for HFE mutations
levels > 1000ug/L usually require referral to a haematologist or gastroenterologist to investigate as levels this high may cause fibrosis and cirrhosis
other causes:
iron overload:
haemochromatosis - transferrin saturation usually > 45% and total iron is raised (AR usually due to homozygosity for the C282Y mutation in the HFE gene, rarely, this may be due to non-HFE haemochromatosis)
transfusional iron overload from multiple blood transfusions
iron overdose
iron loading anaemias
α-thalassaemia
β-thalassaemia
chronic haemolytic anaemias
congenital sideroblastic anaemia
congenital dyserythropoietic anaemia
liver disease
especially alcoholic liver disease
alcohol intake > 20g/day may explain serum ferritin levels up to 1000ug/L