Retrospective Evaluation of Patients Referred for Hemochromatosis Genetic Testing
Bibliographic record
Abstract
Abstract Background: The common genetic test for hemochromatosis involves the genotyping of two polymorphisms in the HFE gene (C282Y and H63D). Current guidelines suggest testing of patients with ferritin greater than 300 µg/L and transferrin saturation greater than 45%. Testing of first degree relatives of confirmed HFE positive cases is also endorsed. However, the current test has poor sensitivity and specificity for iron overload causing end organ damage. We sought to evaluate biochemical parameters of patients referred for HFEtesting and identify those who received phlebotomy. Methods: After receiving ethics approval, electronic charts of patients referred to Hamilton Health Sciences, Hamilton, Ontario, Canada for HFE genetic testing between January 1, 2012 and December 31, 2012 were reviewed. Results: HFE genetic testing in 642 patients yielded 100 (15.6%) positive C282Y homozygote or C282Y/H63D compound heterozygote results. In patients with biochemical markers of iron overload available (n=160), patients with a risk HFE genotype had significantly higher iron saturation, serum iron, and hemoglobin (P<0.001), but did not have higher ferritin or liver enzymes. Only fifty percent of patients referred had biochemical evidence of iron overload (transferrin saturation [TS] > 45% and ferritin > 300). Of patients who required phlebotomy, only 27 of 40 (67.5%) were HFEpositive. Conclusion: Many factors affect the decision to phlebotomize a patient with suspected iron overload. However, it appears that most of the current HFE genetic testing being performed did not alter patient management. Disclosures Crowther: Asahi Kasai: Membership on an entity's Board of Directors or advisory committees; Bayer: Speakers Bureau; Celgene: Speakers Bureau; Shire: Speakers Bureau; Boehriniger Ingelheim: Consultancy; CSL Behring: Speakers Bureau; Leo Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Portola: Membership on an entity's Board of Directors or advisory committees; Viropharma: Membership on an entity's Board of Directors or advisory committees.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".