Since the original discovery of the haemochromatosis gene (HFE) in 1996,1 there have been two genetic mutations that have dominated clinical studies. The C282Y mutation (845 G→A) has attracted the most attention as the majority of typical haemochromatosis patients are homozygotes for this mutation. This has increasingly led to the use of genetic testing for the diagnosis of haemochromatosis and in many cases has alleviated the need for liver biopsy. In comparison with most other genetic diseases, it remains a marvel that a single mutation explains most clinical cases. Furthermore, in vitro studies have demonstrated that the C282Y mutation disrupts the normal presentation of the HFE protein on the cell surface.2 The H63D mutation (187 G→C) was described in the original description of the HFE gene but has been relegated to a minor clinical role in comparison with the C282Y mutation. It is more prevalent than the C282Y mutation with approximately one in five of …