Presenting in Childhood

In congenital cystic malformations of the kidney, as in other groups of disorders, the accuracy of genetic counselling depends upon exact diagnosis. This requires the breakdown of the main heterogeneous group into specific entities, each of which is homogeneous from the genetic viewpoint and therefore carries a predictable recurrence risk within the family. It is particularly important to recognize the group of 'wholly genetically determined' conditions, those due to chromosomal and single gene mutations, since these may be associated with high risks for sibs or children of index patients. The subject of the present study is 'true polycystic disease of the kidneys' as defined from the pathological viewpoint by Kissane (1966). In this group, two entities were already well established when the present survey was begun, and a possible third was emerging. The first entity to be established was the dominantly inherited adult form of polycystic disease of the kidneys. This was recognized as an hereditary trait at least as early as i 899 by Steiner, and its manifestations in adults have been well described from the clinical, pathological, and genetic viewpoints (Oppenheimer, 1934; Fergusson, 1949; Dalgaard, 1957; Heggo, 1966). It is noteworthy that necropsy series agree that in about one third of the patients with this form of the disease there is associated localized cystic malformation of the liver. Although so well defined in adults, the occurrence of this adult type in children had been recorded only rarely and usually without pathological detail or illustration (Steiner, 1899; Halbertsma, 1932; Savera, 1946; Fergusson, 1949). The second type of polycystic malformation of