MOLECULAR INVESTIGATION OF THE PARENTAL ORIGIN OF A DE-NOVO UNBALANCED TRANSLOCATION-13 18/

We report a patient with a de novo translocation 13/18, identified by high-resolution banding. The breakpoints were ascertained by fluoresce nce in situ hybridisation with whole chromosome 13 and 18 paints. Shor t tandem repeat typing demonstrated the aberration to be of combined m aternal/paternal origin and thereby confirmed its de novo and postzygo tic formation. Thus, a gonadal mosaic in one of the parents resulting in a higher recurrence risk could be excluded.