1. The family history of, and associated congenital abnormalities in, patients with talipes equinovarus, talipes calcaneo-valgus and metatarsus varus living in Devonshire has been studied.
2. The chances of any individual having one of these deformities is approximately one per 1,000 in each case.
3. If one child in a family has the deformity, the chances of a second having it are one in thirty-five for talipes equinovarus and one in twenty for talipes calcaneo-valgus and metatarsus varus.
4. The male relatives of the female patients with talipes equinovarus are at particular risk.
5. It is suggested that the cause of club foot is partly genetic and partly environmental, from a factor acting on the foetus in the uterus.
6. The classification of associated congenital abnormalities leads to the suggestion that the genetic factor in talipes equinovarus and talipes calcaneo-valgus relates to defective formation of connective tissue.