Of these infants, six without MPS symptoms were confirmed according to the deficiency of leukocyte GALNS enzyme activity (0.62 ± 0.39 μmol/g protein/h) and increased quantity of urinary KS (21.90 ± 13.68 μg/mL; reference value < 7.9 μg/mL). The gene discussed is GALNS; the disease is mucopolysaccharidosis.