/Following conventional karyomap analysis for the monogenic disease and/or any chromosomal imbalance related to structural rearrangements in the parents (data not shown), combined parental haplotyping (karyomapping) and intensity ratio profiles were analysed in 1279 samples (90.8%) allowing the relative intensity of the paternal and maternal chromosomes to be compared to the corresponding parental haplotype patterns (Figures 1-3). In 130 samples (9.2%), the parental intensities were too variable to provide a reliable comparison (genotyping and karyomapping was still possible in many cases), maternal contamination was detected or WGA failed.