Detection of submicroscopic subtelomeric chromosome translocations: A new case study

Two sisters presented with multiple congenital abnormalities and developmen tal delay; abnormalities elsewhere in their extended family suggested that their father carried a balanced translocation, G-banded chromosome analysis showed apparently normal karyotypes, Fluorescence in situ hybridisation (F ISH) with whole chromosome paints revealed no apparent abnormality in the f ather, However, further FISH studies, using multiple subtelomeric probes, d emonstrated a derivative chromosome 16 in one sister. Subsequent studies sh owed that her sister also had a derivative 16 which had been inherited in a n unbalanced form from their father, who carried a balanced reciprocal tran slocation between chromosomes 1 and 16. This report describes the detection of this submicroscopic translocation and the clinical findings in the two sisters. (C) 2000 Wiley-Liss, Inc.