Abstract / Summary
Purpose: To specify a reproducible approach to five-domain postmortem measurement and research classification in initially unexplained sudden infant deaths using Operational Metabolic Vulnerability Index (MVI) 2.0.
Methods: The published MVI framework and supporting literature were organized into a revised operational specification. Published measurement evidence was distinguished from proposed normalization, aggregation, and classification rules. The specification addresses hepatic CYP protein abundance, inflammatory markers, oxidative-injury markers, medullary histology and immunohistochemistry, and analytically supported xenobiotic findings. No participant cohort or diagnostic-performance study is reported.
Results: The framework specifies component-level evidence requirements, five domain scores, reason-coded not-scorable states, and complete-profile reporting. A total of 0–15 is permitted only when all five domains are scorable. Valid individual findings are retained when a complete profile cannot be assigned. Exploratory measurements and exposure histories remain separate from score-eligible evidence. Potentially explanatory findings undergo independent confirmation and medicolegal review. Prospective evaluation distinguishes collection performance, analytical evaluability, interpretive scorability, and reproducibility.
Conclusion: Operational MVI 2.0 provides a provisional research specification for standardized measurement and descriptive classification. Individual findings may inform further investigation, but the composite score and pattern assignments remain unvalidated and do not establish cause of death. Feasibility and reproducibility studies should precede comparative evaluation of biological significance.