### Consensus consistency validation — 9 October 2026

This is a transparently unblinded consistency check, not a new peer review or independent blinded audit. The frozen review cutoff remains **2026-09-27**. Its source/claim inventory and grade are preserved; Consensus search results are treated as discovery pointers only.

**Grade:** Θ / High (unchanged). The integrated claim is that high phenylalanine causes the severe untreated PKU phenotype and early dietary control prevents it. The review identifies rare untreated people with severe biochemical disease who escape intellectual disability; this unexplained exception blocks Ω. Adult challenge outcomes inform a narrow exposure-sensitivity subclaim and cannot replace evidence about childhood developmental injury.

**Frozen inventory:** 27 evidence entries and 35 registered claims. Two Consensus search results and two fetched records are retained as raw JSON in this folder. Original comparisons below were cross-checked against the review's existing primary-source records; no newly surfaced sources have been added to the original counts.

**Primary comparisons; already in the frozen review inventory:**

| PMID / DOI | Original primary source and claim relation | Access documented in frozen review | Result and scope |
|---|---|---|---|
| 13098090 / 10.1016/S0140-6736(53)90473-5 | Bickel et al. 1953, #1; human phenylalanine add-back | Complete two-page original scanned paper read; PubMed/Europe PMC bibliographic metadata checked; PubMed has no abstract | A single historical dietary add-back case showed neurologic/behavioral change with altered phenylalanine intake. Supports a specific exposure effect but not neonatal prevention or reversal of established intellectual disability. |
| 21153445 / 10.1007/s10545-010-9253-9 | ten Hoedt et al. 2011, #9; blinded adult challenge | Original-paper abstract and bibliographic/status metadata read in Europe PMC; Entrez/web cross-check | Randomized, double-blind crossover Phe supplementation affected adult mood/sustained attention. Does not recreate developmental exposure or prove childhood ID. |
| 38569786 / 10.1016/j.ajcnut.2023.11.007 | Trepp et al. 2024, #10; adult randomized crossover | Original-paper abstract and bibliographic/status metadata read in Europe PMC; Entrez/web cross-check | In 30 early-treated adults, four weeks of higher Phe was noninferior on the primary working-memory-accuracy outcome; sustained attention was the exception among secondary outcomes. Does not establish childhood or lifelong safety. |
| 4140266 / 10.1016/S0140-6736(74)91873-X | Smith & Wolff 1974, #2; early-versus-late treatment natural-history comparison | Original-paper abstract and bibliographic/status metadata read in indexed records; cross-checked with Entrez/web | Historical sibling/timing evidence supports the importance of early treatment, with ascertainment and historical-care confounding retained. |

The fresh Consensus search surfaced adult challenge evidence and guideline/review synthesis. The primary adult trials sharpen the limitation on generalizing short-term adult endpoints to untreated childhood development; they do not contradict the established developmental-treatment evidence or remove the documented rare exception. Grade remains Θ and original counts remain 27/35.



This dated supplement adds source reconciliation to the original review. Its original narrative, registered scope, source inventory and grades remain historical records. No earlier adversarial approval has been verified for this edition at the supplement date. This provenance supplement has no separate approval and is not an independent or blinded adjudication. New sources described here are supplemental and are not counted in the original inventory.