After adjusting for potential confounders MBL deficiency as defined by MBL levels <0.5 μg/ml (OR 0.44, 95% confidence interval (CI) 0.20-0.95, p=0.04) or low producing genotypes (OR 0.24, 95% CI 0.08-0.75, p=0.01) remained independently associated with a decreased risk of acquiring a S. aureus BSI. This evidence concerns the gene MBL2 and hyperinsulinemic hypoglycemia, familial, 4.