IDENTIFICATION OF THE CHROMOSOME-14 ORIGIN OF A C-NEGATIVE MARKER ASSOCIATED WITH A 14Q32 DELETION BY CHROMOSOME PAINTING

A constitutional chromosome 14 rearrangement was observed in a female with a psychodevelopmental disorder. Karyotype analysis using a variet y of chromosome techniques, QFQ, GTG, CBG, Ag-NOR and DA-DAPI, showed a deletion of chromosome 14q32.1-qter region in association with a sup ernumerary marker chromosome. The marker, resembling a submetacentric, approximately half the size of a G group chromosome is C band and Ag- NOR negative. The heteromorphism of the satellites showed that the del eted chromosome 14 is paternal in origin. Chromosome painting using an Alu-PCR probe specific for the human chromosome 14 and fluorescent in situ hybridization (FISH) showed that the marker contains chromosome 14q32 sequences. It is likely that the marker was generated from the d eleted chromosome 14 region through a complex rearrangement.