SINGLE-CELL ANALYSIS DEMONSTRATING SOMATIC MOSAICISM INVOLVING 11P INA PATIENT WITH PATERNAL ISODISOMY AND BECKWITH-WIEDEMANN SYNDROME

Partial isodisomy of 11p has been observed in some patients with Beckw ith-Wiedemann syndrome. In this study, we demonstrate somatic mosaicis m directly through PCR and single cell analysis on blood lymphocytes f rom a patient with Beckwith-Wiedemann syndrome. Whole genome amplifica tion was performed on single cells and the resultant product was subje cted to locus specific microsatellite marker analysis using PCR. Two p opulations of cells were detected, a population of cells with normal b iparental inheritance for chromosome 11 and a population of cells with partial paternal isodisomy of 11p between markers D11S922 (11p15.5) a nd D11S904 (11p14-p13). These results are consistent with somatic reco mbination resulting in mosaicism for paternal isodisomy. The use of si ngle cell PCR is ideal for studying the distribution of mosaicism with in and between tissues and has been used in this study to identify a c ell line with uniparental disomy in a patient with Beckwith-Wiedemann syndrome.