PTH-39 Delayed diagnosis in Hereditary Haemochromatosis – potential utility of ‘case-finding’ approach

IntroductionHereditary haemochromatosis is a common genetic disorder, with a prevalence of 0.25-1% in the UK population. It has variable clinical penetrance, with men more frequently affected. Progression to liver cirrhosis can be prevented with early diagnosis and venesection. Increased testing of serum ferritin may lead to increased diagnosis, although haemochromatosis may still be overlooked, as elevated ferritin levels may be ascribed to malignancy or inflammatory disorders. If late diagnosis is common then a case-finding approach may identify patients earlier in their disease, with lower costs than a screening programme. The aim of this project was to identify whether patients with hereditary haemochromatosis are diagnosed within 6 months of an initial abnormal ferritin, and to estimate the number of patients that remain undiagnosed in Somerset.MethodsSomerset patients with haemochromatosis diagnosed between 2005-2020 were identified from clinic letters and venesection databases. Review of electronic blood results and clinic letters identified demographic data, time to diagnosis and ferritin result at diagnosis. For those with a delayed diagnosis (defined as over 6 months after a ferritin >500), the number of pre-diagnosis ferritin results was recorded.Results124 patients (30 female, 94 male) were identified. 83 patients (20F, 63M) were diagnosed in Somerset after their first available ferritin estimation. 47 (56.6%) were diagnosed within six months of their first raised ferritin. Of those with a delayed diagnosis, 9 (25%) took over 3 years to be diagnosed and 4 (9%) remained undiagnosed after 5 years. The higher the initial ferritin result, the more likely a patient was diagnosed within 6 months (p=0.005). Using published data for the prevalence and clinical penetrance of genetic haemochromatosis, we predicted the expected number of patients with overt haemochromatosis in Somerset. From our modelling we would expect to see 72 women and 412 men with overt clinical haemochromatosis in our population. This indicates that in Somerset 58% of women and 77% of men with clinically relevant haemochromatosis may be undiagnosed.ConclusionsOur data show that diagnosis was delayed in almost half of Somerset patients with haemochromatosis. Additionally, it is a significantly underdiagnosed condition. Given that early initiation of venesection can reduce the risk of developing complications, improving the diagnostic pathway for patients with haemochromatosis using