PARTIAL TRISOMY-22 WITHOUT CAT EYE

A child with typical signs of the cat eye-syndrom except the character istic feature of a cat eye is reported. In a chromosome analysis (47,x x, + mar de novo) an extrachromosome was detected. Using fluorescence in situ hybridization the supernumerary marker refered to chromosome 2 2. In the literature only a few cases show all the characteristic feat ures of cat eye syndrome. However, there are only two case reports of children without any ocular alterations. The great variability in the phenotype probably depends on different sizes of the marker chromosome or asymmetric breakpoints on the long arm of chromosome 22. According to new literature reports there is no correlation between the phenoty pic variability and the size of the marker chromosome. Probably the de gree of severity is correlated with the percentage of the patients lym phocytes that contain the extrachromosome.