A DE-NOVO COMPLEX T(7-13-8) TRANSLOCATION WITH A DELETION IN THE TRPSGENE REGION

Molecular cytogenetic analyses have resolved the pathogenetic aberrati on of an 8-year-old girl with tricho-rhino-phalangeal syndrome type I (TRPS I), normal intelligence, and a karyotype originally described as 46,XX,t(8;13)(q24;q21). R- and Q-banding and high resolution R-bandin g analyses have also disclosed a seemingly mosaic abnormality of the d istal short arm of chromosome 7 but have not fully characterized this abnormality. Combined primed in situ labelling and chromosome painting , and three-colour chromosome painting have revealed a complex, appare ntly balanced translocation t(7;13;8). Fluorescence in situ hybridizat ion with yeast artificial chromosome and cosmid clones from 8q24.1 has shown an interstitial deletion of at least 3 Mb covering most of the TRPS I critical region.