Children with congenital nephrotic syndrome have a special appearance: after birth, they often have a special appearance, such as low nasal bridge, wide eye spacing, low ears, wide cranial sutures, wide fontanelle and posterior fontanelle, and flexion deformities of the hips, knees and elbows. Later, abdominal distention, ascites, and umbilical hernia are common. What are the tests related to the symptoms of hip, knee and elbow flexion deformity? Laboratory tests 1, urine routine: simple nephropathy, 24h quantitative more than 0.1g/kg, occasionally transient small amount of red blood cells, nephritic nephropathy, in addition to the appearance of varying degrees of proteinuria, but also visible microscopic or carnal hematuria. 2.Blood biochemical measurement: It shows hypoproteinemia (serum albumin <30g/L, infant <25g/L), inversion of albumin to globulin ratio, serum protein electrophoresis showing increased globulin, and significantly increased blood cholesterol (children >5.7mmol/L, infant >5.1mmol/L). 3, renal function measurement: the oliguric phase may have temporary mild azotemia, simple nephropathy renal function is mostly normal, if there is varying degrees of renal insufficiency, the presence of elevated blood creatinine and urea nitrogen, it suggests nephrogenic nephropathy. 4.Serum complement measurement: It helps to distinguish simple nephropathy from nephroinflammatory nephropathy. The former has normal serum complement, while the latter often has varying degrees of hypocomplementemia and persistently lower C3. 5.Serum and urine protein electrophoresis: reflect the selectivity of urine protein by detecting the IgG component in urine, and also identify pseudo massive proteinuria and light chain proteinuria. If the ratio of γ globulin to albumin in urine is less than 0.1, it is selective proteinuria (suggesting simple nephropathy), and greater than 0.5 is non-selective proteinuria (suggesting nephritic nephropathy). 6, serum immunological examination: detection of anti-nuclear antibody, anti-double-stranded DNA antibody, anti-Sm antibody, anti-RNP antibody, anti-histone antibody, hepatitis B virus markers, and rheumatoid factor, circulating immune complexes, etc., to distinguish primary from secondary nephrotic syndrome. 7, coagulation, fibrinolytic related protein detection: such as blood fibrinogen and factor V, VII, VIII and X, antithrombin III, urinary fibrin degradation products (FDP) detection can reflect the body’s coagulation status, to provide a basis for whether to take anticoagulation therapy. 8, urine enzyme measurement: the determination of urinary lysozyme, N-acetyl-β-amino glucosidase (NAG), etc. can help determine whether there is also renal tubular-interstitial damage. Other tests 1.B ultrasound and other imaging tests: to exclude congenital malformations of the kidney. 2, percutaneous renal puncture biopsy: for children diagnosed with nephritis-type nephropathy or those with poor glucocorticoid treatment, renal puncture biopsy should be performed promptly to further clarify the pathological type to guide the development of treatment plan.