Exemplary results of UPDtool for chromosome 7 in two positive controls and three selected patients. (a) illustrates two positive controls with combined hetero-iso-disomies from maternal origin on chromosome 7. The upper image shows a sequence of hetero- and isodisomic stretches: heterodisomy from 45 kb to 26 Mb; isodisomy from 26 to 80 Mb; heterodisomy from 80 to 139 Mb; isodisomy from 139 to 159 Mb. The lower image from a different positive control is characterized by a similar allelic pattern of UPD: isodisomy from 40 kb to 7 Mb; heterodisomy from 7.5 to 48 Mb; isodisomy from 48 to 88 Mb; heterodisomy from 88 to 126 Mb; isodisomy from 126 to 159 Mb. The first isodisomic stretch of the second positive control (panel a, lower image) was only detected after adjustment of standard parameters, because this contained <300 MEs. (b) shows exemplary plots for chromosome 7 of selected patients from our cohort. There are no indications for UPD in these images. Legend: FracHom=fraction of genotypes in 1k-window that is homozygous, FracME=fraction of MEs in a 1k-window, FracIdentFather=fraction of genotypes within a 1k-window where both alleles are identical to the fathers' alleles, FracIdentMother=fraction of genotypes within a 1k-window where both alleles are identical to the mothers' alleles, FracError=fraction of errors (other than MEs) within a 1k-window.