Spectrum of ocular manifestations in cobalamin C and cobalamin A types of methylmalonic acidemia
Bibliographic record
Abstract
BACKGROUND: Cobalamin C disease (cblC), which leads to methylmalonic acidemia with homocystinuria, is the most common inherited disorder of vitamin B12 metabolism. Reported ocular findings associated with cblC have been maculopathy, pigmentary retinopathy, and optic nerve atrophy. Cobalamin A disease (cblA) which causes an isolated methylmalonic acidemia without homocystinuria is rarer than cblC. This is the first detailed report of the ocular findings associated with cblA. We also describe the spectrum of ocular findings in our cblC patients. MATERIALS AND METHODS: A case series describing the ophthalmologic clinical course of six patients with a diagnosis of cobalamin C type and one patient with cobalamin A type of methylmalonic acidemia. Patients were diagnosed through biochemical laboratory testing and genetic analysis was conducted on most patients. Longitudinal fundus findings, optical coherence tomography (OCT), autofluorescence, and electrophysiology were followed in the patients. RESULTS: The cblA patient demonstrated a relatively mild ocular phenotype with late-onset and slowly progressing temporal disc pallor and peripapillary atrophy in the second decade of life. The patient maintained good visual acuity and central vision, without evidence of maculopathy. The six cblC patients demonstrated a range of ocular findings from unremarkable and mild phenotypes to significant retinopathy, including bull's eye maculopathy, severe maculopathy with punched out chorioretinal atrophy, peripheral bone spicules, and optic nerve atrophy. CONCLUSIONS: The spectrum of ocular manifestations seen with inherited disorders of cobalamin metabolism is wide, ranging from mild optic nerve atrophy to severe macular or retinal degeneration. This heterogeneity may in part reflect the associated biochemical phenotype, such as that observed between our cblA and cblC patients. We also observed heterogeneity within the cblC type in agreement with previous reports.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".