A novel SCN5A gene mutation causing LQT3 with unique phenotype in a large canadian kindred
Bibliographic record
Abstract
Abstract Background SCN5A gene mutations are associated with diverse clinical phenotypes including Long QT (LQT) Syndrome, Brugada Syndrome, progressive conduction system disease and cardiomyopathy. Objective We identified a novel SCN5A variant (T731I) in a pedigree affected by QT prolongation and ventricular arrhythmia. Clinical phenotype and co-segregation with genotype within the pedigree were characterized. Methods Family members were invited to attend clinics held in their indigenous community. All subjects underwent a history, physical exam, 12 lead ECG and had blood samples collected for genetic testing. Patients were assessed by an adult or pediatric cardiologist and genetic counselors over a six year period. There were 86 females and 69 males ranging in age from 1 to 82 years (mean 36 years) at the time of first assessment. ECG analysis was performed by a cardiac electrophysiologist blinded to patient identity and genotype. The QTc was calculated using Bazett's formula. Results One hundred and fifty five family members were evaluated (86 (55%) female; mean age 36 years (range 1 to 82 years). Mean QTc was 461 + 21 ms for the gene positive group and 419 + 22 ms for the gene negative group (P<0.001) (Figure). There was no significant difference in age or sex between the gene positive and gene negative groups. Gene positive family members were also noted to have low right atrial p waves and frequent unifocal ventricular ectopy and non-sustained monomorphic ventricular tachycardia. One gene positive individual developed dilated cardiomyopathy with high burden ventricular tachycardia and required cardiac transplantation. Conclusion This novel SCN5A variant co-segregated with an abnormal phenotype consisting of significant QTc prolongation, low atrial rhythm, and ventricular arrhythmia. This pedigree highlights the phenotypic heterogeneity of SCN5A gene mutations and the importance of cascade family screening to identify at risk family members. Figure 1. QTc intervals Funding Acknowledgement Type of funding source: None
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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 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.004 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".