Evaluation of the SLC11A1 non-synonymous variant rs17235409 and tuberculosis susceptibility in a multi-ethnic population from southwestern China

Tuberculosis (TB) remains a major infectious disease burden, and inter-individual heterogeneity in progression from exposure to active disease suggests contributions from host genetic factors. SLC11A1 (formerly NRAMP1) encodes a phagosomal divalent cation transporter implicated in macrophage-mediated antimicrobial defense; the non-synonymous rs17235409 polymorphism (D543N) has been evaluated in multiple populations with inconsistent results. We conducted a retrospective matched case-control study in Qiandongnan, Guizhou Province, China, including 50 patients diagnosed with TB (2022-2023) and 50 healthy controls frequency-matched by ethnicity and selected demographics. Participants were drawn from Miao, Dong, and other minority groups. Among TB cases, the frequencies of the GG, GA, and AA genotypes were 80.0%, 20.0%, and 0%, respectively, compared with 74.0%, 18.0%, and 8.0% among controls. The overall genotype distribution did not differ significantly between the 2 groups (P = .124). Under the dominant model, no significant association was observed between rs17235409 and TB susceptibility (OR = 0.71, 95% CI: 0.28-1.82; P = .635). Allelic analysis showed that the frequency of the A allele was lower in cases than in controls (10.0% vs 17.0%), but this difference was not statistically significant (OR = 0.54, 95% CI: 0.24-1.25; P = .214). Ethnicity-stratified analyses similarly showed no statistically detectable associations in Miao, Dong, or other groups. The minor allele frequency was 0.095, lower than the Han Chinese reference from 1000 Genomes. In this pilot study of multi-ethnic populations from southwestern China, no statistically significant association was identified between the SLC11A1 rs17235409 polymorphism and tuberculosis susceptibility. Although the A allele appeared less frequent among cases, the limited sample size and statistical power preclude definitive conclusions regarding modest or ethnic-specific effects. These findings provide preliminary genetic data from underrepresented ethnic minority populations and warrant validation in larger multicenter studies.