Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder, occurring in approximately 1 in every 400 to 1000 live births [1-3]. It is estimated that less than one-half of these cases will be diagnosed during the patient's lifetime, as the disease is often clinically silent .
Approximately 85 percent of families with ADPKD have an abnormality on chromosome 16 (PKD1 locus) that is tightly linked to the alpha-globin gene locus . The remaining patients have a different defect that involves a gene on chromosome 4 (the PKD2 locus). (See "Genetics of autosomal dominant polycystic kidney disease and mechanisms of cyst growth".)
Patients with PKD2 have a less severe phenotype than those with PKD1, but neither disorder is benign . Cysts occur later in PKD2 disease, as does end-stage renal disease (mean age 74.0 versus 54.3 years in PKD1) . As a result, false negative results are more likely when screening young subjects with PKD2 disease. (See "Course and treatment of autosomal dominant polycystic kidney disease".)
The diagnosis of and screening for ADPKD will be reviewed here. The course and treatment of this disorder are discussed separately. (See "Course and treatment of autosomal dominant polycystic kidney disease".)
The diagnosis of ADPKD relies principally upon imaging of the kidney . Typical findings include large kidneys and extensive cysts scattered throughout both kidneys. Because of cost and safety, ultrasonography is most commonly used as the imaging modality. In certain settings, genetic testing is required for a definitive diagnosis.