Pallister‐killian syndrome: Characterization of the isochromosome 12p by fluorescent In Situ hybridization

Abstract

The isochromosome 12p (i(12p)) in fibroblasts of 3 patients with Pallister-Killian syndrome and one decreased prematurely born neonate, was characterized by fluorescent in situ hybridization (FISH) using chromosome 12-specific DNA probes. FISH is a useful technique for rapid and reliable detection and characterization of the i(12p) chromosome in Pallister-Killian patients. Detection was possible also in interphase cells. In addition, the in vitro selection against i(12p) cells at different passages in fibroblast cultures of two patients was monitored.

The Use of Interphase Fish for Prenatal Diagnosis of Pallister–killian Syndrome

“…Prenatal diagnosis has been previously reported in 23 cases of PKS (Gilgenkrantz et al, 1985;Lopes et al, 1985;Hunter et al, 1986;Steinbach and Rehder, 1987;Shivashankar et al, 1988;Eydoux et al, 1989;Soukup and Neidich, 1990;Bresson et al, 1991;Sharland et al, 1991;Speleman et al, 1991;Blancato et al, 1992;Bernert et al, 1992;McLean et al, 1992;Priest et al, 1992;Tejada et al, 1992;Bergoffen et al, 1993;Donnenfeld et al, 1993;Larramendy et al, 1993;Wilson et al, 1994;Los et al, 1995). Both chorionic villi and amniocytes appear to maintain the isochromosome; however, the level of mosaicism varies greatly between individuals.…”

“…It has proven to be extremely useful for the identification of marker chromosomes and the evaluation of interphase cells. Both of these applications have been successfully used for prenatal diagnosis of Pallister-Killian syndrome (Speleman et al, 1991;Blancato et al, 1992;Bernert et al, 1992;McLean et al, 1992;Wilson et al, 1994;Horn et al, 1995;Los et al, 1995). It also provides a rapid method for evaluating a large number of cells in order to determine more accurately the level of mosaicism in a wide variety of tissues, thus providing us with a better understanding of the pathogenesis of this rare disorder.…”

Partial tetrasomy 12pter-12p12.3 in a girl with Pallister-Killian syndrome: extraordinary finding of an analphoid, inverted duplicated marker

“…There is only a single report with an apparently analphoid isochromosome 12p in the literature. 4 A specific region, which might be responsible for the PKS phenotype when present in tetrasomic state, has not yet been described.…”

Sequential G-banding and fluorescent in situ hybridization on peripheral blood, bone marrow, and amniotic fluid samples

“…In cases of complex chromosome karyotypes, G-banding alone does not always permit complete characterization of rearrangements and FISH analysis may provide information to better characterize abnormalities. This is especially true in leukemia studies where sample Other techniques combining G-banding and FISH analysis have been described [Babu and Wiktor, 1991;Speleman et al, 1991;Jalal et al, 1993;Epstein et al, 1995;El-Rifai et al, 1996;Gerdes et al, 1997]. These protocols required formaldehyde-acetone pretreatment, increased probe concentration, a double denaturation step when rehybridizing slides with a second probe, or described the use of only one type of probe.…”