Anaemia and iron deficiency associate with polymorphism TMPRSS6 rs855791 in Brazilian children attending day care centres.

Iron-deficiency anaemia is a major public health concern in children under 5 years of age. TMPRSS6 gene, encoding matriptase-2 protein, is implicated in iron homeostasis and has been associated with anaemia and iron status in various populations. The aim of this cross-sectional study was to investigate the associations between the single nucleotide polymorphism (SNP) TMPRSS6 rs855791 and biomarkers of anaemia and iron deficiency in Brazilian children attending day care centres. A total of 163 children aged 6-42 months were evaluated. Socioeconomic, demographic, biochemical, haematological, immunological, and genotype data were collected. Multiple logistic and linear regressions with hierarchical selection were used to assess the effects of independent variables on categorized outcomes and blood marker concentrations. Minor allele (T) frequency of rs855791 was 0·399. Each copy of the T allele was associated with a 4·49-fold increased risk of developing anaemia ( P = 0·005) and a 4·23-fold increased risk of iron deficiency assessed by serum soluble transferrin receptor (sTfR) ( P < 0·001). The dose of the T allele was associated with an increase of 0·18 mg/L in sTfR concentrations and reductions of 1·41 fL and 0·52 pg in mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH), respectively. In conclusion, the T allele of SNP TMPRSS6 rs855791 was significantly associated with anaemia and iron deficiency assessed by sTfR in Brazilian children attending day care centres. The effect was dose-dependent, with each copy of the T allele being associated with lower MCV and MCH and higher concentrations of sTfR.