A CASE OF PRESUMPTIVE MONOSOMY-21 RE-DIAGNOSED AS UNBALANCED T(5P-21Q) BY FISH AND REVIEW OF LITERATURE

By using fluorescence in situ hybridization (FISH), we demonstrate a c ase of monosomy 21 to result from an unbalanced translocation involvin g the short arm of chromosome 5 and the long arm of chromosome 21, Our case is compared to 3 similar cases of t(5p;21q) reported recently, w hich were also originally diagnosed as monosomy 21. The breakpoint on chromosome 5 in these cases occurred in the p13-p15 region, whereas th e breakpoint on chromosome 21 was in the q21-q22 region. Comparison of the clinical findings in these patients demonstrated great similariti es, Furthermore, a strong correlation between the clinical manifestati ons of these patients with cridu-chat syndrome patients was also noted , We suggest that cases with unbalanced t(5p;21q) represent a distinct syndrome which can be grouped under a new category of ''5p/21q deleti on syndrome.'' (C) 1997 Wiley-Liss, Inc.