Identification of a cat eye syndrome using DNA sequence dosage analysis

We report here the detection of a Cat Eye Syndrome (CES) in a woman who does not exhibit the related phenotype, due to intensive surgery. The analysis of her karyotype reveals a small supernumerary bisatellited chromosome likely to correspond to a fragment of chromosome 13, 15, 21 or 22 on banding analysis. Southern blot of genomic DNA of this patient and her parents hybridized with probes specific of these chromosomes, revealed a DNA amplification of the 22q11 region for the patient, likely to correspond to a CES.