Hypothesis: The female excess in cranial neural tube defects reflects an epigenetic drag of the inactivating x chromosome on the molecular mechanisms of neural fold elevation
Bibliographic record
Abstract
Females have long been known to be in excess among cranial neural tube defect (NTD) cases. Up to two thirds of human anencephalics and mouse exencephalics from various genetic causes are female, but the cause of this female excess is unknown. It appears not to be attributable to gonadal hormones, developmental delay in females, or preferential death of affected males. Recent studies of the Trp53 mouse mutant showed that exencephaly susceptibility depends on the presence of two X chromosomes, not the absence of the Y. Over a decade ago, we hypothesized that the relevant difference between female and male mammalian embryos at the time of cranial neural tube closure is the fact that females methylate most of the DNA in the large inactive X chromosome after every cell division, reducing the methylation available for other needs in female cells. Recently, the Whitelaw laboratory identified several proteins in mice (Momme D genes) involved in epigenetic silencing and methylation and shared in the silencing of transgenes, retrotransposons, and the inactive-X, and suggested that the inactive-X acts as a "sink" for epigenetic silencing proteins. The "inactive-X sink" hypothesis can be used to suggest expected changes in sex ratio in cranial NTDs in response to various genetic or environmental alterations. We recommend that observation of sex ratio become a standard component of all NTD studies. We suggest that the female excess among cranial NTDs is an epigenetic phenomenon whose molecular investigation will produce insight into the mechanisms underlying NTDs.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".