PARENTAL ORIGIN OF THE EXTRA CHROMOSOME IN TRISOMY-18

  • 1 October 1989
    • journal article
    • research article
    • Vol. 45  (4) , 599-605
Abstract
The parental origin of the supernumerary chromosome 18 was investigated by RFLP analysis in 23 individuals with Edwards syndrome. All families were studied with the DNA probe pERT-25, which recognizes a locus of highly polymorphic tandemly repeated DNA sequences on chromosome 18. The extra chromosome was found to be of maternal origin in 19 patients (95%), of paternal origin in one patient (5%), and indeterminate in three patients. In one of the three indeterminate cases, a mosaic, an apparent recombination event had taken place within the pERT-25 locus. The overall high degree of informativeness of pERT-25 illustrates the power of a chromosome-specific variable-number tandem repeat probe (VNTR) in parental origin studies of aneuploidy.