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

We describe here a case of a tandem 22/15 translocation with deletion of the 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 hypotonia, developmental delay, delay of gross motor milestones and speech delay. No dysmorphic features of face, hands or feet were evident in the patient. G-banded peripheral blood lymphocyte chromosomes showed a tandem translocation between chromosomes 22 and 15, with the satellite stalks of chromosome 15 apparently being retained. All-telomere FISH analysis using a TTAGGG repeat probe showed absent signals at the junction of the translocation. Sequential G-banding and FISH analysis using a beta satellite probe showed positive signals close to the junction of the translocation, an indication that the short arms of the chromosome 15 involved in the translocation are retained. FISH with a probe for arylsulfatase, mapped to 22q13.3 region, was negative on the translocation chromosome. Therefore, the 22q13.3 region is deleted. (C) 2001 Wiley-Liss, Inc.