[History and epidemiology of congenital hip dislocation in Brittany].

Brittany is a region of France with a high rate of congenital dislocations of the hip (CDH). This was shown by Le Damany, who, in 1912, did a systematic screening of newborns and compared the number of CDH in Paris and Rennes. In Paris, there was 0.8% and in Rennes 3.6% CDH. This frequency is not generalized in Brittany, however; and Setter, who did a large survey in Finistère in 1961 and 1962, showed that the epicenter was the canton of Pont l'Abbé, also called "pays Bigouden". However, this disease did not occur in this region of France in earlier times. In 1795, Cambry, according to the "Convention de la Jeune République", travelled in Finistère from village to village and did not notice any limping women. This was a very serious and precise study, and we may conclude that there was no CDH at that time; the disease occurred later in "pays Bigouden". From these basic facts, certain hypotheses are considered. From the point of view of genetics, a mutation apparently occurred in the 19th century, but there is no reliable genetic study. Autosomic heredity with incomplete penetrance, with variable penetrance according to sex may be considered: it includes a multifactorial origin of the disease involving genetics, environmental, biochemical and ethnic factors, including local customs and traditions.