P.079 4H leukodystrophy: a case series of siblings with an unusually mild phenotype
Bibliographic record
Abstract
Background: 4H leukodystrophy is a genetic disorder typically characterized by hypomyelination, hypodontia and hypogonatotropic hypogonadism. Previously reported patients had considerable cognitive and motor deficits. We present a pair of siblings with a less severe phenotype. Methods: Patient data was obtained from medical records from the Children’s Hospital of Eastern Ontario. Results: The first patient was diagnosed with 4H leukodystrophy at the age of 21 years after genetic testing revealed a POLR3B mutation with a homozygous V523E variant. She has hypomyelination on MRI and a history of optic neuritis, as well as intermittent sensory and motor symptoms in the context of a diagnosis of multiple sclerosis. She has no clinical manifestations of 4H leukodystrophy. The patient is now 26 years old and has only mild neurological deficits. Her younger brother was diagnosed with 4H leukodystrophy at the age of 18 years and found to have the same genetic mutation as his sister. He has a history of seizures and mild learning disabilities. He is now 23 years old with no typical symptoms of 4H leukodystrophy. Conclusions: 4H leukodystrophy is usually associated with a severe, disabling phenotype and a poor prognosis. Our patients illustrate that a much milder phenotype exists.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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".