MONOSOMY 1P36.31-33-]PTER DUE TO A PATERNAL RECIPROCAL TRANSLOCATION - PROGNOSTIC-SIGNIFICANCE OF FISH ANALYSIS

A rare monosomy 1p36.31-33-->pter was found in a child with physical a nomalies, psyche-motor retardation, and seizures. Cytogenetic investig ation suggested an unbalanced translocation between 1p and an acrocent ric chromosome, but the rearrangement was difficult to assess accurate ly using conventional chromosome banding techniques. The half-cryptic translocation was further characterized using fluorescence in situ hyb ridization, and the aberrant chromosome 1 was shown to be a derivate o f a paternal reciprocal translocation t(1;15) (p36.3-33;p11.2-12). The breakpoints on chromosome 1 and 15 were defined in detail using locus specific probes. The rearrangement did not include the region on chro mosome Ip which previously has been suggested to predispose to the dev elopment of neuroblastoma in a case with a constitutional translocatio n. At 36/12 years, the patient has no clinical signs of this disease, which illustrates the prognostic significance of this investigation. ( C) 1996 Wiley-Liss, Inc.