Renatal diagnosis of mosaic tetrasomy 12p/trisomy 12p by fluorescent in situ hybridization in amniotic fluid cells: A case report of pallister–killian syndrome

Abstract

A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as the well-known accessory isochromosome 12p and a supernumerary single 12p marker in 17/24 and 6/24 clones of cultured amniotic fluid cells, respectively. The chromosomal nature of both marker chromosomes was investigated in cultured amniotic fluid cells by fluorescent in situ hybridization with various probes: the 12-centromeric probes p alpha 12H8 and D12Z3, a whole chromosome 12 paint, and the chromosome 12p-specific paint M28. DNA analysis revealed a maternal origin of the extra 12p material. After counselling, the parents requested termination of pregnancy. Inspection and autopsy of the fetus revealed many of the dysmorphisms and internal structural abnormalities of the Pallister-Killian syndrome.

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

“…Due to the association with increased maternal age, it has been assumed that the i(12p) is most likely maternal in origin . However, this has only been confirmed in one case (Los et al, 1995). If the parental origin of the isochromosome determines the phenotype, then it suggests that there may be an imprinted gene(s) located on the short arm of chromosome 12.…”

“…A premature male infant with multiple congenital anomalies was born at 34 weeks, but died after 5 h (Shivashankar et al, 1988). A total of 20 cases have been diagnosed following amniocentesis for either AMA or detection of fetal anomalies (Gilgenkrantz et al, 1985;Lopes et al, 1985;Hunter et al, 1986;Steinbach and Rehder, 1987;Warburton et al, 1987, case 3;Shivashankar et al, 1988;Eydoux et al, 1989;Soukup and Neidich, 1990;Speleman et al, 1991, case 4;Blancato et al, 1991Blancato et al, , 1992McLean et al, 1992;Priest et al, 1992;Tejada et al, 1992;Bergoffen et al, 1993, case 3;Donnenfeld et al, 1993, cases 8 and 12;Larramendy et al, 1993;Wilson et al, 1994, cases 1 and 2; Los et al, 1995). The prevalence of the isochromosome ranged from 18 to 100 per cent.…”

“…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.…”

Retrospective Diagnosis of Pallister-Killian Syndrome by CGH Array

“…However, neither the exact mosaicism rate in pulmonary tissue nor the presence of a tetrasomy/trisomy/disomy 12p mosaic, which has been reported in 3 cases [9][10][11] , can be specifi ed with CGH methods. In the case of trisomy, the factor would be expected to increase to 1.5, and in the case of tetrasomy to 2.0.…”