MBL2 and hyperinsulinemic hypoglycemia, familial, 4: Our reported median CSF level of MBL of 15 ng/ml is slightly lower than the median level of approximately 25 ng/ml in patients with pneumococcal meningitis and no MBL deficiency reported in a study evaluating CSF levels of MBL in relation to pneumococcal meningitis, but slightly higher than in such patients with MBL deficiency (<5–15 ng/ml depending on genotype) [30].