Decreased Bone Mineral Density in Neurofibromatosis Type 1
Bibliographic record
Abstract
Neurofibromatosis type 1 (NF1) is a common genetic disorder affecting 1 in 3000 live births. It is well documented to be associated with bony deformities and other orthopaedic problems. Based on our observation that NF1 patients undergoing orthopaedic surgery often had osteopenic bone, we performed a study to assess the bone mineral density of a cohort of children with NF1 without orthopaedic defects.Twenty-three patients were recruited from the neurofibromatosis clinic. The bone mineral density of the total body, lumbar spine, and proximal femur was measured using dual-energy x-ray absorptiometry. Quantitative ultrasound was used to measure broadband ultrasonic attenuation at both heels. The group's mean dual-energy x-ray absorptiometry sex- and age-matched Z scores were below normal (-0.8 +/- 1.1, -0.8 +/- 1.2, -0.7 +/- 0.8, -0.6 +/- 1.1, -0.6 +/- 0.9, -0.6 +/- 1.1 for the total body, arms, legs, lumbar spine, and right and left femoral neck, respectively; all P < 0.01). Although some individuals had normal bone mass, 30% had total body Z scores below -1.5. The mean heel broadband ultrasonic attenuation Z score was also lower than normal (-0.8 +/- 0.6; P < 0.001). Children with NF1 have a general tendency toward osteopenia, suggesting an abnormal underlying bone phenotype. This may be relevant when considering operative intervention and, if better understood, may partially explain poor bone healing associated with NF1.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".