Partial trisomy of chromosome 22 resulting from a supernumerary marker chromosome 22 in a child with features of cat eye syndrome

S111all SLIpernLitnerary niarker chroinosonies are I-)resent in aboLit 0.05% of the hLinian pol:)tilation. In approxiniately 28% of 1)ersons with these niarkers (exClUcling the 60% cleriN7ecl froin one of the acrocentric chroniosornes), an ahnorn-ial Iflienotype is observecl. We report on a 3-nionth-old girl,,vith intraUterine growth retarclation, craniol'acial fCatLtres, hypotonia, p irtial colobonia of iris ancl total anoinalotts pUlnionary venOLIS rettirn. Cytogenetic analysis showed the presence of a SLII)ernuinerary inarker chromosonie, iclentified by flLiorescence in SitL1 hybridization as part of chroniosoine 22, ancl conferring a p-oxinial partial trisoin ' 22q22.21, not enconil)assing the DiCeorge critical region (RPII-154H4+, TBXI-). This observation acids new inforination relevant to cat eye synclroine and I)artial trisonIN of 22q. (c) 2008 Wiley-Liss, Inc.