Prenatal diagnosis by amniocentesis and chorionic villus biopsy of mtDNA mutation 8993T>G
Bibliographic record
Abstract
The mtDNA mutation 8993T > G is associated with neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) and Leigh syndrome. There are few reported cases of prenatal testing for mtDNA disorders. Specifically for 8993T > G, there are six cases in which prenatal diagnosis has been reported. We describe prenatal diagnosis in a 36-year-old G3P1 woman with 33% heteroplasmy in white blood cells. She had a previous child who died from Leigh disease (92% heteroplasmy). She underwent prenatal testing by both CVS and amniocentesis of the 8993T > G heteroplasmy levels. This is the first reported case in which both procedures were used. Heteroplasmy was similar in both tissues (58.6% CVS and 55% amniocentesis), in support of the theory that this testing is reliable and may be considered in prenatal cases where this mutation is known in the mother. To date, her child is 20 months old and developing normally. Heteroplasmy determination in the child was refused. Although the infant is developmentally normal, consistent with the observation that levels of heteroplasmy below 60% are compatible with a mild phenotype, this conclusion must be tempered by the limited period of observation and the fact that patients with the NARP phenotype often present later than 20 months of age.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".