Stable transmission of an unbalanced chromosome 21 derived from chromoanasynthesis in a patient with a SYNGAP1 likely pathogenic variant
Bibliographic record
Abstract
Complex genomic structural variations, involving chromoanagenesis, have been implicated in multiple congenital anomalies and abnormal neurodevelopment. Familial inheritance of complex chromosomal structural alteration resulting from germline chromoanagenesis-type mechanisms are limited. We report a two-year eleven-month old male presenting with epilepsy, ataxia and dysmorphic features of unknown etiology. Chromosomal microarray identified a complex unbalanced rearrangement involving chromosome 21. G-banding and FISH for targeted regions of chromosome 21 revealed that the copy number imbalances were limited to gains dispersed throughout the long arm of chromosome 21, characteristic of a chromosome derived from chromoanagenesis. Family studies showed that the unbalanced chromosome had been stably inherited, as it was present in both his healthy mother and maternal grandfather. Further molecular testing for non-syndromic intellectual disability genes found a likely pathogenic mutation in SYNGAP1 (NM_006772.2:c.3722_3723del). This study indicates that complex rearrangements involving an unbalanced chromosome derived from chromoanasynthesis can be familial and should be not be presumed pathogenic.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".