A case of two daughters of consanguineous parents, one with « pure gonadal dysgenesis », and the other with severe ovarian hypogenesis are reported. Both patients have positive nuclear pattern, and normal feminine karyotype, i e. 44 A + xx.
After reviewing the literature on familiar cases of « rudimentary gonads syndrome », the AA. suggest that the genetic mechanisms involved are different, according to the clinical picture and the chromosomal constitution.
In the few cases of classical Turner's syndrome with xo karyotype, a repetition of a chromosomal nondisjunction, during maternal or paternal gametogenesis, can be accepted. The cases of chromosomal mosaicism are probably related to an anomalous mitotic division of normal zygotes which takes place in the same woman, in the course of more than one pregnancy.
Various interpretations can be given to the cases of familiar pure gonadal dysgenesis. Since the patients show more often a normal feminine or masculine karyotype, the possibility that the anomaly is bound to an autosomal recessive gene has been suggested (see Hauser's case, 1960, in which, as well as in the one here reported, the parents were consanguineous).
Other possibilities are not to be underestimated: an early lesion of the gonads by environmental maternal factors, also in subjects with different genetic sex, should be taken into account.