SEX-DEPENDENT TRANSMISSION OF BECKWITH-WIEDEMANN SYNDROME-ASSOCIATED WITH A RECIPROCAL TRANSLOCATION T(9,11)(P11.2,P15.5)

Beckwith-Wiedemann syndrome (BWS), a disorder associated with neonatal hypoglycaemia, increased growth potential, and predisposition to Wilm s's tumour (WT) and other malignancies, has been mapped to 11p15. The association with 11p15 duplications of paternal origin, of balanced tr anslocations and inversions with breakpoints within 11p15.4-p15.5 of m aternal origin, and the demonstration of uniparental paternal 11p15 is odisomy in some sporadic cases point towards the involvement of genomi c imprinting. In agreement with this, we show the paternal origin of a de novo 9;11 translocation in a phenotypically normal mother, whose c arrier daughter developed BWS. This supports the fact that BWS associa ted with balanced chromosome mutations is transmitted in the same sex dependent pattern as non-cytogenetic forms of familial BWS.