Renal and urinary tract diseases
Autosomal dominant polycystic kidney disease (PKD) is one of the most common Mendelian genetic disorders in adulthood, but it is extremely variable. Molecular tests are feasible for most cases of PKD1-related disease, but linked markers have been used until recently and renal ultrasound remains of central importance in family testing for those at risk. Infantile polycystic disease is a disorder of both the kidneys and liver. The renal cysts are a manifestation of collecting duct ectasia and are accompanied by variable degrees of hepatic fibrosis and biliary dysgenesis. The histological appearance is distinct from that of adult polycystic disease presenting in infancy. Medullary cystic kidney disease is an autosomal dominant disorder of usually adult onset that is caused largely by mutation in one of two genes, either MUC1 or UMOD. Juvenile nephronophthisis is an autosomal recessive disease that has early onset and will often lead to end-stage renal failure in childhood.