We studied a large Danish pedigree with autosomal dominant congenital cataracts (ADCC) in 9 generations. Morphological characteristics of the cataracts are described and documented by photos. In contrast with several other types of ADCC the cataracts studied were progressive during infancy and childhood. Linkage analysis with 14 marker systems revealed close linkage between this Marner cataract locus (CAM) and the locus of Haptoglobin (HP) on chromosome 16. Genetic heterogeneity in ADCC has now established with the genetic mapping of cataract loci to chromosome 1, chromosome 2, and chromosome 16.