NPHS1 and hyperinsulinemic hypoglycemia, familial, 4: Nephrin deficiency is considered a pathologic feature of glomerular injury [33, 35], and nephrin-mutant mice develops more exaggerated glomerular enlargement and increased apoptosis with mild proteinuria, foot process effacement, mesangial hypercellularity and sclerosis, and glomerular basement membrane thickening [35].