Haemochromatosis: when is referral for venesection required?

Case scenario

Jean, a 63-year-old woman, had been diagnosed with haemochromatosis several years ago. Although she was asymptomatic, she presented to her GP to see whether her blood tests indicated the need for a further venesection. On checking her records, it appeared that Jean’s original genetic testing showed that she was homozygous for the C282Y mutation.

Over the past few years Jean’s iron studies had never shown an elevated ferritin level. In fact, on one occasion, it was even below the normal baseline level. However, her transferrin saturation had often been high, and on this occasion was 80%.

What are the guidelines for referring patients such as Jean for further venesection?