Dupuytren's disease recurs more frequently than generally assumed. 24 typical family trees derived from the literature are analyzed here. The main conclusions that can be derived are the following: 1) Monogenic heredity is confirmed. 2) The sex ratio in the affected families is 61,2 m: 38,8 f. 3) The sex ratio in unaffected families is 38 m: 43 f. 4) The expressivity of the disease is variable. Penetrance, which is incomplete, varies according to the sex. In our selected material, the penetrance rate is 93,6% in the males and 42,9% in the females. 5) Males transmit the gene in 68% of the cases; females in 32%. 6) Incomplete sex linkage can be excluded. 7) A comparison is made between the really observed values and the theoretical rates for normal and affected men and women for the chance of an auto-somatic dominance. These observations make possible the conclusion that the number of affected females is too low as compared with unaffected females and affected males. 8) A new theory is suggested concerning the mechanism of heredity based on the different statistical values. The responsible factor would be deadly for 60% of the XX affected zygotes. But 60% of the affected X gametes produced by the mother, being identified by an essential incompatibility for the unaffected X spermatozoid, would be electively fecundated by a Y gamate. This machanism would explain the excess of affected males, the small proportion of affected females and the sex-ratio of 61,2: 38,8. The concordance between the observed values and the theoretically expected values of such a kind seem to convalidate our new theor
