Addresses a documented Pakistani care gap
The study provides local evidence in a setting described as having limited C1-INH testing, no molecular diagnosis, no specific C1-INH treatment, and no national HAE registry.
↳ Introduction, final paragraph
Abstract
OBJECTIVE: To establish cascade family screening of newly diagnosed hereditary angioedema (HAE) patients. STUDY DESIGN: Cross-sectional, observational study. Place and Duration of the Study: Department of Immunology, The Armed Forces Institute of Pathology / CMH / NUMS, Rawalpindi, Pakistan, from September 2021 to June 2024. METHODOLOGY: Eighty-nine parents, siblings, and children of 10 diagnosed patients of HAE were screened. Thirty-two family members were screened by using C1 esterase and complement C4 levels, whereas 57 patients were not available or willing for blood samples, and a questionnaire designed for HAE was recorded from patients / index cases. Baseline characteristics of HAE-Index and HAE-Screened patients were analysed using inferential statistics (independent t-test, Chi-square / Fisher's exact, and Mann-Whitney U test), selected based on data distribution (assessed by the Shapiro-Wilk's test). RESULTS: A total of 10 cases were followed for screening in families. Upon cascade screening of 89 individuals, 16 confirmed and 24 probable cases of HAE among family members (symptomatic and asymptomatic) were identified. Out of these 40 positive patients, 26 were male and 14 were female. Three patients among these screened individuals died secondary to laryngeal oedema. Out of ten index cases, two did not have any family history of hereditary angioedema, hence suspected for de novo mutation in the SERPING-1 gene. CONCLUSION: Cascade screening helps in facilitating early diagnosis of asymptomatic or mildly symptomatic family members of HAE patients. This will provide better guidance for avoiding potential triggers, appropriate prophylaxis, and better management of HAE patients. Young patients of HAE need genetic counselling for a 50% risk of HAE in offspring and are recommended for prenatal diagnosis. KEY WORDS: C1 esterase, C4, Hereditary angioedema, Laryngeal oedema, Screening.
Key Claims
Primary findingSupported
Upon cascade screening of 89 individuals, 16 confirmed and 24 probable cases of HAE among family members (symptomatic and asymptomatic) were identified.
Fragile — the claim's weakest requirement is that the effect exists at all. Based on how the study was designed and conducted, not on statistics extracted from the paper. Experimental. Every point below is traceable to a quoted passage, but this forecast has not yet been validated against known replication outcomes.
the counts distinguish evidence tiers, but most identified cases rely on an unvalidated questionnaire
Abstract; Results, first paragraph
SecondaryTentative
Cascade screening helps in facilitating early diagnosis of asymptomatic or mildly symptomatic family members of HAE patients.
the cross-sectional design identified relatives but did not compare diagnostic timing or downstream outcomes
Abstract; Conclusion
SecondaryTentative
Out of ten index cases, two did not have any family history of hereditary angioedema, hence suspected for de novo mutation in the SERPING-1 gene.
absence of reported family history cannot establish de novo mutation without molecular testing
Abstract; Results, first paragraph
Derived from the full evaluation — not a separate score.
Strengths · Limitations
Strengths
Uses biochemical testing for confirmed cases
Thirty-two relatives underwent C1 esterase and C4 testing using a named automated analyser with reported normal ranges, yielding 16 confirmed cases.
↳ Methodology; Results, first paragraph
Engages directly comparable international evidence
The Discussion compares the cohort with the Hong Kong CaSE-HAE study and addresses related evidence on family history, C4 sensitivity, and laryngeal-oedema mortality.
↳ Discussion, paragraphs 2–5
Limitations
Most positive labels lack confirmation
Twenty-four of 40 positive relatives were classified as probable through an undescribed questionnaire rather than biochemical or genetic confirmation, yet all 40 contribute to the headline 45% yield.
↳ Abstract; Methodology; Results, first paragraph
Selection into testing remains unexplored
Only 32 of 89 relatives provided blood samples, and the article does not examine whether tested and questionnaire-only relatives differed systematically.
↳ Methodology; Results, first paragraph
Limitations do not qualify headline yield
The limitations section names single-centre scope and unavailable molecular testing but does not explain how questionnaire-only classification affects the certainty of the 45% yield.
↳ Discussion, Limitations paragraph
Nabu Commentary
The study's main value is its Pakistani screening dataset and its relevance to a health system with limited HAE diagnostics and treatment. The central methodological constraint is that only 32 relatives received biochemical testing, while 24 probable cases were classified through an undescribed questionnaire and then included in the 45% yield. The cross-sectional design supports reporting identified cases but not the stronger implications concerning earlier diagnosis, prophylaxis, or improved management. The Discussion provides useful international comparisons, although its limitations analysis does not trace incomplete verification through to the certainty of the headline result.
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Author Note / Field Feedback
Nabu’s assessment, alongside the field’s view.
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Dimension breakdown
Study Quality
Limited2.7
Confidence mediumContribution
2.7
The study adds a Pakistani cascade-screening dataset from a setting with restricted HAE diagnostics and treatment. Its scientific advance is primarily contextual because a closely comparable cascade-screening design and yield had already been reported internationally.
Introduction, final paragraph; Discussion, comparison with Wong et al.
A total of 32 available relatives were screened with C1 esterase and C4 levels and 16 (50%) cases were confirmed
Methodological Rigour
2.5
The cross-sectional family-screening design fits descriptive ascertainment, and assay ranges and equipment are reported. However, only 32 of 89 relatives underwent blood testing, while the questionnaire defining 24 probable cases is neither reported nor validated and selection into testing is unexplored.
Methodology; Results, first paragraph
Fifty-seven family members of index cases, who were not available for blood samples, were screened for probable HAE with a questionnaire
Reporting
3.0
The conventional structure makes the screening process and broad findings followable. Precision is reduced by combining confirmed and probable cases in the 45% yield and by describing downstream early-diagnosis and management benefits that were not directly measured.
Abstract; Results, first paragraph; Conclusion
40 were labelled with HAE, resulting in a diagnostic yield of 45%
Positioning
2.8
The Discussion compares the findings with relevant international HAE screening, family-history, C4-sensitivity, and mortality literature. The limitations section does not address how the undescribed questionnaire affects the 24 probable cases or the certainty of the combined yield.
Discussion; Limitations paragraph
Limitations of this study include that it is a single-centre study from the Northern region of Pakistan
Reliability
Caveats4 of 4 checks
Internal CoherenceNoted
The main counts are reconstructable, but the presentation contains denominator ambiguities and combines different diagnostic evidence tiers in the headline yield. These issues qualify interpretation without overturning the finding that additional relatives were identified.
Research ConductClean
Ethical approval, informed consent, and absence of competing interests are explicitly declared. No supplied-text evidence raises a research-conduct concern.
Flags: 2 declared / 5 total
Reference IntegrityNoted
15 of 17 checkable references verified
17 references in manuscript
Post-Publication RecordClean
No retraction notice found in Retraction Watch.
Last checked: 18 Sep 2026
Sources: Retraction Watch ✓
Readiness
Where this paper’s evidence sits on the path from initial observation to real-world use.
Demonstrated
Screening was performed in a real clinical population, placing the work at pilot or proof-of-concept stage. Readiness is limited by the absence of a validated questionnaire, operational protocol, economic analysis, or measured post-screening outcomes.
Methodology; Results; Conclusion
a questionnaire designed for HAE was recorded from patients / index cases
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