Two supernumerary marker chromosomes, originating from chromosomes 6 and 11, in a child with developmental delay and craniofacial dysmorphism

The interpretation of the significance of marker chromosomes, which can be encountered at prenatal diagnosis, is extremely problematic. Various factor s contribute to the difficulty of clarifying the phenotypic risks of supern umerary marker chromosomes, including differences in the size, structure, a nd origin of marker chromosomes, as well as the occurrence of multiple mark er chromosomes of different origin in the same proband. Research on marker chromosomes is currently in a data-accumulation phase. We report the presen ce of two marker chromosomes, originating from chromosomes 6 and 11, in a c hild with developmental delay and craniofacial dysmorphism and discuss the related literature. Copyright (C) 2001 S. Karger AG, Basel.