Background: Type 2A hereditary haemochromatosis (type 2A HH) is a rare iron-loading disorder caused by mutations in the HFE2 gene, which encodes the HJV protein. We present characteristics, treatment and follow-up of subjects diagnosed with type 2A HH in the Netherlands to increase awareness of the disease and its treatment, and to define knowledge gaps.
Methods: We collected clinical, biochemical and genetic data from seven patients (two female; five probands) from six families genetically diagnosed with type 2A HH at the Expertise Center for Iron Disorders, Radboud University Medical Centre between 2006 and 2016.
Results: The five probands presented with heterogeneous complaints between the ages of 19 and 39. One of two patients with delayed clinical diagnosis developed hypogonadism and Y. enterocolitica sepsis. Diagnostic workup and follow-up varied. When assessed, elevated transferrin saturation (79-98%), ferritin (1400-6200 µg/l) and severely elevated liver iron levels were found, and in all subjects, phlebotomies were initiated. One subject was switched to erythrocytapheresis. Target ferritin levels varied. Despite long-term iron depletion, two subjects developed clinical complications. Sanger sequencing revealed two pathogenic HFE2 variants (homozygous or compound heterozygous) for the five families of Dutch descent and one new pathogenic variant in the family of non-Dutch descent.
Conclusion: Three genetic variants caused type 2A HH in six families. Clinical diagnosis was delayed in two subjects. We observed variance in presentation, workup, follow-up and treatment. We found new complications in long-term iron-depleted patients. We recommend research and guidelines for optimal workup, follow-up and treatment of type 2A HH.