Exclusion of congenital or acquired chimerism by microsatellite marker analysis. Representative electropherogram showing the blood DNA profile of patient 1 after multiplex-PCR of 15 highly polymorphic autosomal short tandem repeat loci and amelogenin (Amel.). Numbers denote allelic designations of individual loci. No additional allelic peaks and only well-balanced heterozygous peaks are observed. Similar results were obtained with samples from the other 8 patients.