Iron-overload Quick revision card
often inherited Hereditary haemochromatosis is the most common cause of iron overload disease ○ vast majority are due to HFE gene ( type 1 ) autosomal recessive inheritance ○ all other types ( very rare ) are non HFE
autosomal recessive inheritance most common autosomal recessive disorders in whites the two common genetic variations in the HFE gene are ○ C282Y and ○ H63D Most affected individuals have two C282Y variants ( homozygotes ) and a H63D variant ( compound heterozygotes ) prevalence of 1 in 300 to 500 disordered iron metabolism with increased iron absorption ( despite a normal intake ) and deposition in the liver , pancreas , heart , joints and pituitary gland (i.e excess iron is stored in the parenchymal cells of the liver and other organs ) rate of absorption is increased from a normal 1-2 mg /day ( in the proximal intestine ) to 4-5 mg /day leading to accumulation of 15-40 gms of iron in the body unlike transfusion related overload the macrophages are not grossly overloaded with iron
patients with haemoglobinopathies as ○ sickle cell disease ○ thalassemia ○ sideroblastic anaemia congenital haemolytic anaemias myelodyplasia here the causes are likely to be reduced utilization of iron due to defective incorporation of iron into heme down regulation of hepcidin frequent transfusions
Organ damage due to iron overload-Ferritin and transferrin saturation are the first line tests in primary care for cases of suspected iron overload.
REFERENCES
- American Association for Clinical Chemistry Iron overload disorders by Quian Sun Iron Overload Disorders | AACC.org
- MSD manuals Secondary Iron Overload Secondary Iron Overload – Hematology and Oncology – MSD Manual Professional Edition (msdmanuals.com)
- Haemochromatosis : Introduction hemochromatosis.pdf (hopkinsmedicine.org)
- Haemochromatosis care pathway Haemochromatosis care pathway (uhs.nhs.uk)
- McDowell LA, Kudaravalli P, Sticco KL. Iron Overload. [Updated 2021 Apr 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526131/
