As the activity of the lysosomal enzymes N-acetyl-β-d-glucosaminidase and cathepsin B were significantly increased in the subgroup of Noncompliant GDM mother neonates, to establish a possible general effect of GDM on tubular lysosomal enzyme excretion or on perturbation on tubular maturation, we assayed the urinary activity of β-glucuronidase and legumain in the two subgroups of GDM neonates and control. This evidence concerns the gene CTSB and gestational diabetes.