Usually, the diagnosis of<unk>  is initially performed by renal imaging using ultrasound, CT scan, or MRI. However, molecular diagnostics can be necessary in the following situations: 1- when a definite diagnosis is required in young individuals, such as a potential living related donor in an affected family with equivocal imaging data; 2- in patients with a negative family history of<unk> , because of potential phenotypic overlap with several other kidney cystic diseases; 3- in families affected by early-onset<unk>  kidney disease, since in this cases hypomorphic alleles and/or oligogenic inheritance can be involved; and 4- in patients requesting genetic counseling, especially in couples wishing a pre-implantation genetic diagnosis. The findings of large echogenic kidneys without distinct macroscopic cysts in an infant/child at 50% risk for<unk>  are diagnostic. In the absence of a family history of<unk> , the presence of bilateral renal enlargement and cysts, with or without the presence of hepatic cysts, and the absence of other manifestations suggestive of a different renal cystic disease provide presumptively, but not definite, evidence for the diagnosis. In some cases, intracranial aneurysms can be an associated sign of<unk> , and screening can be recommended for patients with a family history of intracranial aneurysm. Molecular genetic testing by linkage analysis or direct mutation screening is clinically available; however, genetic heterogeneity is a significant complication to molecular genetic testing. Sometimes, a relatively large number of affected family members need to be tested in order to establish which one of the two possible genes is responsible within each family. The large size and complexity of<unk>  and PKD2 genes, as well as marked allelic heterogeneity, present obstacles to molecular testing by direct DNA analysis. The sensitivity of testing is nearly 100% for all patients with<unk>  who are age 30 years or older and for younger patients with<unk>  mutations; these criteria are only 67% sensitive for patients with PKD2 mutations who are younger than age 30 years. Image:Adult<unk>  Kidney.Adult<unk>  kidney File:Autosomal<unk><unk>  Kidney Disease.Diagram of autosomal<unk><unk>  disease with a normal kidney inset for comparison File:CT scan<unk> .Abdominal CT scan of an adult with<unk> : Extensive cyst formation is seen over both kidneys, with a few cysts in the liver, as well. (Coronal plane)
Autosomal dominant polycystic kidney disease
Autosomal recessive polycystic kidney disease
Medullary cystic kidney disease
Glomerulocystic kidney disease
Medullary sponge kidney
Juvenile nephronophthisis
Horseshoe kidney
Multicystic dysplastic kidney