Deletions at chromosome regions 7q11.23 and 7q36 in a patient with Williams syndrome

We report on a patient with Williams syndrome and a complex de novo chromos ome rearrangement, including microdeletions at 7q11.23 and 7q36 and additio nal chromosomal material at 7q36. The nature of this additional material wa s elucidated by spectral karyotyping and first assigned to chromosome 22. S ubsequent fluorescence in situ hybridization (FISH) experiments showed that it consisted of satellite material only. Refinement of the 7q36 breakpoint was performed with several FISH probes, showing a deletion distal to the t riphalangeal thumb (TPT) region. The phenotype of the patient principally r esults from the microdeletion of the 7q11.23; the small deletion at 7qter a nd the extra satellite material may not be of clinical significance. (C) 20 01 Wiley-Liss, Inc.