Electroretinography and temporal aspects in macular dystrophy

In a family with cone-rod dystrophy of autosomal recess inheritance, the diagnosis was established by characteristic abnormalities of the ERG, which demonstrates cone responses reduced in amplitude and delayed in implicit time, and rod delayed implicit time in two sisters with macular degeneration. The abnormalities of the implicit time are seen also in two other sisters of the propositi, who are clinically normal. The hypothesis that they are only capable to transmit the gene defect to their offspring is advanced.