Il problema delle malformazioni congenite su base ereditaria alla luce di alcune osservazioni nella specie canina

Are described some malformations noticed at random as regards the front limbs of pups born from the same bitch at the end of 4 pregnancies, and in the 2nd generation, from a malformed bitch, daughter of the first. The phenotypical cadences with which the anomalies appear — though te bitches have been covered by nearly always different dogs — are analysed from the genetic point of view. Concerning this, a rational, modem, biometmy and statistical valution, even with the limits imposed by the size of the experimental material, meveals the hemeditary character of the studied dysmorphosis, which it is possible to enframe into the chapter of the pathological eredity with a relative genotypic codification. The latter could also interest the phenotypically normal subjects — see, for instance, the dogs which mated with the two bitches — which, taking into account the relation with which the malformation reveals itself in a constant way, could very well be considered as presumed carriers. The lack of recrossing in the genetic sense — in our case inbred matings between brothersand sisters, between fathers and daughters, between mothers and sons — has, unfortunately, preventend us from thoroughly studying, in a more complete way, the problem of the transmissibility of the same malformations. In any case, without disregarding the consideration of eventual facts of dyaginical heredity, of linkage, of epistasy and hypostasy, of genical interactions, the hereditary character of said anomalies could represent a dynamical intervention of the additive type polymerism. Their different pathological level would lead us to think of a changing indication of genic penetrance and expressvity of the polymeric moment, in relation to likely extra-genetic factors which, acting on the organic, organismic and tissular subtratum, could influence the intermediation — of an enzymatic or antigen nature — which, from the gen leads to the phen.