Genomic Interpretation Across Clinical Settings

Evidence

A global, retrospective autopsy-confirmed brain-bank study examined pathology and genetics in parkinsonian disorders. Of 5,648 donors with available genetic data, 3,353 eligible donors were included; their mean age at death was 76.8 years and 61.8% were male [pmid:42258190]. The study drew on 11 academic brain banks in the United Kingdom, United States, and Australia, with donations spanning 1985 through 2024 [pmid:42258190]. Across movement disorders, reported clinical misdiagnosis rates were approximately 10% to 20% [pmid:42258190].

The genetic-pathological results underscore biological heterogeneity within clinically overlapping syndromes. In this cohort, GBA1 variant carriers had greater Lewy body pathology burden than noncarriers (OR 1.94, 95% CI 1.24-3.03) and than LRRK2 variant carriers (OR 7.44, 95% CI 2.16-25.64) [pmid:42258190]. Alzheimer disease copathology occurred in 426 of 1,064 Lewy body disease cases, or 40.0% [pmid:42258190]. Pathological diagnoses also differed by genetically inferred ancestry: South Asian donors were more likely to have progressive supranuclear palsy pathology and Ashkenazi Jewish donors more likely to have Lewy body disease, independently of GBA1 and LRRK2 variant status [pmid:42258190]. The authors state that integrating genetic and pathological data may help improve diagnostic accuracy and support genetically and pathologically stratified approaches in future therapeutic-trial research [pmid:42258190].

A separate descriptive survey assessed molecular tumor boards (MTBs) and genomic testing in Italian sarcoma referral centers. Six of 10 contacted centers responded, and every responding center reported an MTB [pmid:42318456]. Among respondents, target-panel sequencing and whole-exome sequencing were available in all centers; whole-genome sequencing was available in 83% and RNA sequencing in 53% [pmid:42318456]. The survey also found differing MTB composition, analytic software, and variant-interpretation resources across centers [pmid:42318456]. Analysis required more than 10 days in 67% of responding centers, while 33% reported a turnaround time of 10 days or less [pmid:42318456].

The sarcoma authors characterize these results as a descriptive view of early MTB use rather than an outcomes study. They identify a need to build expertise and standardize processes for rare cancers, and position the findings as a basis for larger prospective harmonization efforts [pmid:42318456].

Analysis — Standardization at the Interpretation Layer

Together, these sources describe a shared implementation problem: genomic data may add useful biological context, but the route from data generation to reliable interpretation is neither automatic nor uniform. In the parkinsonian-disorders study, genetic variant status, genetically inferred ancestry, clinical diagnosis, and autopsy pathology were evaluated together [pmid:42258190]. The observed misdiagnosis range and the 40.0% Alzheimer disease copathology rate in Lewy body disease show why a single clinical label may not capture all relevant pathological features in this selected cohort [pmid:42258190]. The GBA1 and LRRK2 comparisons further show that variant-associated patterns can differ within a clinically related disease area [pmid:42258190].

The sarcoma survey places a parallel emphasis on organizational interpretation. Sequencing modalities were broadly reported among the six responding referral centers, yet board composition, software, knowledge bases, and turnaround varied [pmid:42318456]. Availability of a test therefore should not be treated as equivalent to a standardized interpretive workflow. The authors' call for expertise development and harmonized MTB practice is consistent with that distinction [pmid:42318456].

Across both settings, the evidence supports viewing standardization as an interpretive and governance challenge as well as a technical one. For research programs, this suggests clearly documenting cohort selection, assay availability, analytic methods, variant-classification procedures, multidisciplinary inputs, and timing. Such documentation can make results more comparable across sites. It does not show that any particular genomic workflow improves survival, treatment response, diagnostic decisions in routine care, or outcomes for an individual. The two reports are complementary examples from different disease contexts, not direct evidence that one common model has been validated across neurology and oncology.

Limitations

The parkinsonian-disorders evidence is retrospective, cross-sectional, autopsy-based, and drawn from selected brain-bank donors rather than a prospective clinical population [pmid:42258190]. Its associations do not establish that variants or ancestry cause particular pathology or clinical outcomes. Ancestry was genetically inferred, and the contributing brain banks did not collect self-reported race and ethnicity data [pmid:42258190].

The sarcoma evidence is a 2021 survey with responses from only six of 10 contacted centers; it is not representative of Italy as a whole [pmid:42318456]. It describes participating referral centers, not patient-level outcomes, and does not demonstrate that MTB review or genomic testing changed treatment, improved response, or improved survival [pmid:42318456]. Neither source independently validates clinical use of the reported associations or workflows. This briefing therefore confines its conclusions to research interpretation and implementation context.