79Disorders of Vitamin B12 Metabolism Presenting Through NBS—Janice Fletcher Disorders of Vitamin B12 Metabolism Presenting Through Newborn Screening
Bibliographic record
Abstract
Detection of disorders of B12 metabolism in the newborn period by tandem mass spectrometry relies on finding elevated propionyl (C3) carnitine or methylmalonyl (C4DC) carnitine. Although sensitive, C3 carnitine is not specific for a single condition. It is a marker of vitamin B12 deficiency and propionic academia as well as the methylmalonic acidurias, caused by deficiencies of the methylmalonyl coenzyme A mutase apoenzyme (muto, mut-), or its cofactor adenosylcobalamin, as well as the cobalamin abnormalities, cblC, cblD, and cblF deficiencies, all of which have associated homocystinuria. Mass newborn urine screening for methylmalonic aciduria has been performed on 1,745,753 newborn samples collected at age 21 days in Quebec since 1975.1 This programme has provided valuable information on the
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
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".