Table 1

The major clinical traits and cytogenetic characteristics of marker chromosomes

Case No Major clinical signs Chromosomal origin Numbers per cell Parental origin Frequency (%) Size and morphology
1Baker's cysts, facial dysmorphic features51Unknown57∼21q, ring
2Heart defect, developmental delay, dysmorphic features62De novo68Minute
3Craniofacial dysmorphic features191De novo36∼21q, ring
4Urogenital abnormalities, retinal degeneration201Unknown100<21q