The diagnosis is made on the basis of family and birth histories and clinical features of the hip, knee, and elbow with flexion deformity. The differential should first exclude secondary cases of known etiology, as treatment of the primary disease (e.g., anti-syphilis treatment secondary to syphilis) can be expected to remit the nephropathy. In combination with other clinical and laboratory manifestations of the primary disease itself, the diagnosis can be clarified. Drash’s syndrome should be considered in young infants with unexplained nephrotic syndrome with external genital abnormalities. This syndrome, reported by Drash in 1970, presents as a renal embryonal tumor (Wilm tumor), male pseudohermaphroditism, and renal involvement (which may present as a nephrotic syndrome); some cases have only a dichotomous presentation. The renal pathology is characterized by diffuse mesangial sclerosis and tubular atrophy, with more glomerular lesions in the superficial renal cortex than in the proximal medulla. In addition to the Finnish congenital nephrotic syndrome, the primary congenital nephrotic syndrome can also be caused by diffuse mesangial sclerosis, which has no perinatal abnormalities, normal placental size, and can start as early as the neonatal period, but mostly after 3 months of life, and the disease enters renal decompensation early and dies due to uremia. The early stage of the disease is thylakoid sclerosis, collapse of glomerular capillary loops, and no cell proliferation; the later stage is glomerulosclerosis and tubular and interstitial fibrosis. Occasionally, microscopic lesions and focal segmental sclerosis are seen, and the effect of adrenocorticosteroid treatment is the same as in older children. The onset of infantile nephrotic syndrome (INS) and CNS both occurs in the first year of life, but the onset of INS is later than that of CNS, often in the second half of the first year, and especially rarely in the first 3 months of life. It is now believed that this is mainly due to a disruption of the integrity of the glomerular basement membrane, which increases the permeability and results in the filtration of large amounts of proteinuria. Congenital hip dislocation is one of the more common congenital anomalies in children. It is more common in posterior dislocations and is present at birth, with more females than males, about 6:1, and twice as many on the left side than on the right side, with fewer bilateral cases. It is mainly due to congenital dysplasia or abnormalities of the acetabulum, femoral head, joint capsule, ligaments and nearby muscles, resulting in joint laxity, subluxation or dislocation. In addition, the abnormal position of the fetus in the womb and hyperflexion of the hip joint also predispose to the disease, and genetic factors are also more obvious. Congenital knee deformity is a congenital structural and functional alteration of the knee joint. The knee eclipse is the largest and most structurally complex and perfect joint in the human body, consisting of the lower femur, the upper tibia and the patella in front. The main forms of motion of the carpus are flexion and extension of the knee, with slight rotational activity in the semi-flexed position. Congenital elbow fusion is a rare congenital disorder whose pathogenesis is unclear and is generally thought to be caused by the failure of the proximal end to separate during the maturation of the mesodermal cartilage branches leaving the trunk and forming the ulnar radius around the 5th week of development in the embryo. It is clear that this sign is an autosomal recessive disorder, and genetic disease counseling and prenatal diagnosis should be emphasized. The concentration of AFP in fetal blood reaches its peak at 13 weeks of gestation, and when proteinuria occurs in the fetus, AFP enters the amniotic fluid with urine protein, so prenatal diagnosis is often made by testing the concentration of AFP in amniotic fluid. In pregnant women who have delivered a child with this disease, AFP in amniotic fluid can be used for prenatal diagnosis at 11 to 18 weeks of gestation. In recent years, research on the NpHSI gene sequence has made it possible to make a definitive prenatal diagnosis. Those with secondary infections should be actively prevented by strengthening prevention and hygiene promotion, pregnancy care and prenatal checkups, etc.