SUMMARYThe authors have observed a case of “Fuchs' atrophia gyrata chorioideae et retinae” in a girl, 17 years old, who presents in the same time an Alder's anomaly (azurophilic granulations in the neutrophiles). This girl was born from an intermarriage: the parents are first cousins and present also an isolated Alder's anomaly, which is moreover found in other members of the family (8 members affected in 4 generations).These facts prove that Alder's anomaly can be transmitted in a dominant manner, which was not yet accepted till now, and also that the “Fuchs' atrophia gyrata chorioideae et retinae” probably represents the homozygous state of the gene of Alder's anomaly, the isolated presence of which permits to recognize the carriers of the gene of the atrophia gyrata.