In the general population, the percentage of individuals with a history or persistent concomitant hematuria may be as high as 2-5%, especially microscopic hematuria. There are many causes, among the medical causes the most common being IgAN and hereditary diseases, while the most common hereditary nephritis includes thin basement membrane nephropathy (TBMN) and ALPORT syndrome. The primary function of the kidney is its filtration function, with 2-3 million renal filtration units involved in completing filtration. Structurally, each renal unit consists of a glomerulus, which connects to the vascular system, and a tubule, which connects to the collecting ducts and ureters. The glomerulus is the starting point of blood flow through the kidney and then filtered out urine. There are three closely interconnected layers between the blood flow inside the glomerular capillaries and the original urine outside the capillaries, namely the capillary endothelial cell layer from the inside out, the glomerular basement membrane layer in the center, and the pedicle cell layer on the outside. These three layers are what doctors often call the “blood-urine barrier”. The inner layer of endothelial cells is like a porous membrane laid flat throughout the lumen of the blood vessels, and its cross-section is mostly like a dashed circle; the outer layer of podocytes is shaped like a spreading octopus with a thin membranous layer between the feet (what doctors call the interpeduncular fissure membrane); the central layer is the basement membrane or basement membrane (GBM), which is about 250 to 450 nm thick when observed by electron microscopy. In children under 6 years old The GBM is significantly thinner in children under 6 years of age than in adults, and slightly thinner in female adults than in male adults, while in children and adults over 12 years of age, basement membrane thickness <200 nm is considered pathological basement membrane changes. The lower limit of normal basement membrane thickness (WHO standard) is 250 nm in adults and 180 nm in children aged 2 to 11 years. morphological criteria for thin basement membranes are left to pathologists, who take into account the age and gender of the patient and differences in specimen preparation techniques between laboratories.