Tandem translocation of chromosomes 22 and 15 with two preserved satellitestalk regions and deletion 22q13.3-qter

We describe here a case of a tandem 22/15 translocation with deletion of th e 22q13.3-qter region and retention of the NOR of chromosome 15. A 2(1)/(2) -year-old Korean girl was referred for chromosome analysis after a clinical evaluation for developmental delay. Physical examination revealed hypotoni a, developmental delay, delay of gross motor milestones and speech delay. N o dysmorphic features of face, hands or feet were evident in the patient. G -banded peripheral blood lymphocyte chromosomes showed a tandem translocati on between chromosomes 22 and 15, with the satellite stalks of chromosome 1 5 apparently being retained. All-telomere FISH analysis using a TTAGGG repe at probe showed absent signals at the junction of the translocation. Sequen tial G-banding and FISH analysis using a beta satellite probe showed positi ve signals close to the junction of the translocation, an indication that t he short arms of the chromosome 15 involved in the translocation are retain ed. FISH with a probe for arylsulfatase, mapped to 22q13.3 region, was nega tive on the translocation chromosome. Therefore, the 22q13.3 region is dele ted. (C) 2001 Wiley-Liss, Inc.