Contribution of higher risk genes and European admixture to Crohnʼs disease in African Americans
Bibliographic record
Abstract
BACKGROUND: African Americans (AAs) are an admixed population of West African (WA) and European ancestry (EA). Crohn's disease (CD) susceptibility genes have not been established. We therefore evaluated the contribution of European admixture and major established risk genes to AA CD. METHODS: Ninety-seven admixture informative markers were genotyped for ancestry estimates using STRUCTURE. Overall, 354 AA CD cases and 354 ethnicity-matched controls were genotyped for total 21 single nucleotide polymorphisms (SNPs) in ATG16L1, NOD2, IBD5, IL23R and IRGM by TaqMan or direct sequencing. Association was evaluated by logistic regression, adjusted for ancestry. RESULTS: Mean EA was similar among the CD cases and controls (20.9% and 20.4%, respectively, P = 0.58). No significant admixture differences were observed among 211 to 227 cases stratified by phenotypic subclassifications including onset, surgery, site, and behavior. CD was associated with NOD2 carrier (6.93% CD, 2.15% Controls, P = 0.007), ATG16L1 Thr300Ala (36.1% CD, 29.3% Controls, P = 0.003), SLC22A4 and SLC22A5 (IBD5 locus) functional SNPs (Leu503Phe [10.5% CD, 7.6% Controls, P = 0.05] and g-207c [41.3% CD, 35.7% Controls, P = 0.03], respectively), and IL23R rs2201841 (18.2% CD, 13.8% Controls, P = 0.03), but not IRGM variants, nor three African ancestral NOD2 nonsynonymous variants. IBD5 risk was recessive. An all-minor allele IBD5 haplotype from EA was associated (P = 0.05), whereas a more common haplotype isolating g-207c was not. CONCLUSIONS: Specific functional gene variations contribute significantly to AA CD risk. Established NOD2, SLC22A4-A5, and ATG16L1 variants show increased CD risk, with IBD5 recessive. Although CD is more common in whites, European admixture is similar among AA cases and controls.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".