The urinary tract is a common site for congenital malformations different meaning. Many anomalies are asymptomatic and are diagnosed by prenatal ultrasound or during a routine screening for other congenital anomalies. Other anomalies are discovered after an obstruction, infection or trauma. A bilateral renal agenesis, the part of a syndrome with oligohydramnios, pulmonary and abnormalities of limbs and facial (Potter’s syndrome) is a few minutes after birth is fatal to hours. Fetal death is common. The unilateralie renal agenesis is not uncommon and accounts for about 5% of renal anomalies from. In many cases, a prenatal complete regression of multicystic dysplastic kidney is responsible for it. They can occur together with a Ureteragenesie, in which also the ipsilateral Trigonum and the ureter are not created. However, the ipsilateral adrenal gland is not affected. The remaining kidney compensates hypertrophic and maintains a normal renal function, treatment is not necessary. Since the kidneys have a common embryonic origin with the vas deferens and the uterus, boys can agenesis of the vas deferens and girls have uterine abnormalities. Autosomal recessive polycystic kidney disease The incidence of autosomal recessive polycystic kidney disease n is about one of 10,000-20,000 births. The autosomal dominant polycystic kidney disease is much more common. It occurs in about one in every 500-1000 live births (see Fig. Autosomal dominant kidney disease (ADPKD)). An autosomal recessive disease affects the kidneys, the liver, the kidneys are usually greatly enlarged and contain small cysts; Kidney failure in childhood is common. The liver is enlarged; it show up periportal fibrosis, a proliferation of the bile ducts and scattered cysts. The remaining liver tissue is normal. The fibrosis causes portal hypertension at the age of 5-10 years, but the liver function is normal or only slightly impaired. The severity of the disease and progression vary. The severity of the disease is manifested prenatally or shortly after birth or in early childhood with renal symptoms; Patients less severely affected will be introduced in late childhood or adolescence with liver symptoms. The affected newborns have a protruding abdomen with huge, firm, smooth, symmetrical kidneys. Severely affected newborns have as a result of renal dysfunction and the Oligohydramnions in the uterus often a pulmonary hypoplasia on. In patients aged between 5 and 10 years signs of portal hypertension can such. B. oesophageal and gastric varices and hypersplenism occur. If the patient presents in adolescence, the nephromegaly is less pronounced renal insufficiency may be low or moderate and the main symptoms can be associated rather with the portal hypertension. The diagnosis can be difficult, especially if the family history is missing. Renal or hepatic cysts can be sonographically detected, the final diagnosis, a biopsy is necessary. An ultrasound in late pregnancy allows a prospective diagnosis in utero. If necessary, molecular tests can be performed on PKHD1 if the clinical criteria are not met. Many newborns die in the first days or weeks because of pulmonary insufficiency. Most who survive develop progressive kidney failure followed by dialysis or kidney transplantation. Experience with kidney transplants with or without liver transplantation are limited. When a transplantation is performed, the hypersplenism must be controlled (hypersplenism) to prevent the induced by a hypersplenism problems of leukopenia, which increase the risk of systemic infection. Of portal pressure must be treated with a portocaval or splenorenal shunt, but not reduced morbidity, mortality. Excess Duplikationsanomalien collection systems can be unilateral or bilateral and include the renal pelvis or ureter (additional renal pelvis, double or triple pelvis or ureter), the calyces or the ureteral orifice. Duplicated kidneys have a single renal unit with more than one urine collection system. This anomaly is different from the associated kidney, including the connection of two renal parenchymal units heard while retaining their respective individual urine collection system. Some Duplikationsanomalien have an ectopic ureter with or without ureterocele and / or vesicoureteral reflux. Treatment depends on the anatomy and function of each section. Surgery may be necessary to correct an obstruction or vesicoureteral reflux. Fusion anomalies The fusion anomalies kidneys are united, but the ureters open one on each side of the bubble. These abnormalities increase the risk of obstruction in height UPJ, a vesicoureteral reflux, a congenital renal cystic dysplasia (Congenital Cystic renal dysplasia) and a breach in an anterior abdominal trauma. A horseshoe kidney, the most common fusion anomaly occurs, when the renal parenchyma merges on either side of the spine on the corresponding (usually lower) pole; while the parenchymal isthmus or fibrous tissue in the midline unite. The ureters cross medial and anterior across the Isthmus. There is no obstruction of the outflow. However, if there is an obstruction, this is usually the result of the same confluence of the ureter into the pelvis. A pyeloplasty can then be performed without resection of the isthmus. The crossed renal ectopia is the second most common fusion anomaly. The renal parenchyma (representing both kidneys) is located on one side of the abdomen. One of the ureter crosses the midline and ends on the opposite side into the bladder. If an obstruction at the level of UPJ is present, a pyeloplasty must be performed. A fused pelvic kidney (kidney pie) is rare. A single pelvic kidney is supplied by two collection systems and ureters. In obstruction surgical correction and reconstruction is displayed. Malrotation A Malrotation has little clinical significance. Ultrasound often reveals hydronephrosis. Further clarification is performed with a magnetic resonance urography or renal scan, especially if doctors suspect a possible obstruction. Multicystic dysplastic kidney (MDCK) In this disease, there is a non-functioning renal unit of non-communicating cysts with intermediate resistant fabric from fibrous, cartilaginous and primitive tubules herds. Normally there is a Ureterenatresie. The contralateral kidney is usually normal, but up to 10% of patients may have a vesicoureteral reflux or a ureteropelvic. Often the kidney is gradually returned and is no longer visible eventually in sonography. A development of tumors, infection and / or high blood pressure are rare. Most experts recommend watching, unless the fixed tissue appears very extensive and unusual in sonography or there is a progressive cystic enlargement before, which is why the kidney must be removed. Renal The renal dysplasia, a histological diagnosis, the renal vessels, tubules, collecting systems or drainage systems develop pathological. The diagnosis is made by biopsy. If it is a segmental dysplasia, no treatment is necessary. In severe dysplasia kidney dysfunction may require the nephrology care including a kidney transplant. Renal ectopia creates a renal ectopia (unusual location of kidney) when the kidney in embryonic development does not rise from its original location in the pool or equal to the thorax (thoracic kidney). There is often an obstruction in the amount UPJ, a vesicoureteral reflux or multicystic renal dysplasia in Beck kidney unlike thoracic kidneys. An obstruction and a heavy reflux can be corrected surgically with indication (at high pressure, repeated infections or renal growth delay). Renal hypoplasia hypoplasia is usually the result of a lack of division of the primitive kidney. The kidney is small, the nephrons are histologically normal. Hypoplastic segment can cause hypertension and must be surgically removed. In addition, a vesicoureteral reflux should be ruled out.