RT Journal Article SR Electronic T1 The aetiology of the cat eye syndrome reconsidered. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 108 OP 118 DO 10.1136/jmg.18.2.108 VO 18 IS 2 A1 G Guanti YR 1981 UL http://jmg.bmj.com/content/18/2/108.abstract AB The cat eye syndrome (CES), usually ascribed to the presence of a deleted supernumerary 22 chromosome, is characterised by a typical clinical picture including anal atresia, ocular coloboma, preauricular tags or sinuses, congenital heart defects, urinary tracts anomalies, and mental and physical retardation. An analysis of published reports revealed that of the 57 reported cases, only 21 showed the complete form, and 11 had a normal karyotype. Several observations question the existence of a trisomy 22:(1) the absence of any report in living subjects of trisomy 22 arising from an inherited Robertsonian translocation; (2) the recurrent abortions in carriers of Robertsonian translocations involving chromosome 22; and (3) the existence of a syndrome, showing the same clinical features as trisomy 22, which is irrefutably dependent on a trisomy of the distal region of the 11 long arm. On the basis of a comparison of the clinical features in full trisomy 13, partial 13 trisomies, 13 rings, 13 deletions, and CES the small marker present in this syndrome is considered to be a chromosome 13 with an interstitial deletion. An attempt to map this chromosome has been made.