Spontaneous tumours 46% testes,16% adrenal, 5% pituitary, 6% skin and ear duct and fewer of other types in males; 21% pituitary, 13% uterus, 11% mammary gland, 6% adrenal and fewer of other types in females. Other conditions include 28% of males and 20% of females with absent, hypoplastic or cystic kidneys on one side sometimes associated with an absent or defective uterine horn or atrophic testes on the same side. These abnormalities have a polygenic mode of inheritance.