Haemochromatosis is the most common genetic disease in individuals of Northern European origin. This disorder of iron metabolism, for which the molecular basis remains poorly understood, is characterized by an excessive absorption of dietary iron through the duodenal mucosa. Progressive iron loading of parenchymal organs results in the mid-life onset of clinical complications, and patients may succumb to cardiac failure and/or hepato-carcinoma. But patients who undergo early diagnosis and phlebotomy treatment before the development of organ damage have a normal life expectancy. The haemochromatosis gene was recently isolated and encodes a HLA class I related protein. A missense mutation (C282Y) in the homozygous configuration was observed in more than 92% of the patients. So diagnosis and genetic counselling are getting modified by this direct genotyping test.