%0 Journal Article %A B Horsthemke %A A Maat-Kievit %A E Sleegers %A A van den Ouweland %A K Buiting %A C Lich %A P Mollevanger %A G Beverstock %A G Gillessen-Kaesbach %A G Schwanitz %T Familial translocations involving 15q11-q13 can give rise to interstitial deletions causing Prader-Willi or Angelman syndrome. %D 1996 %R 10.1136/jmg.33.10.848 %J Journal of Medical Genetics %P 848-851 %V 33 %N 10 %X A de novo interstitial deletion of 15q11-q13 is the major cause of Prader-Willi syndrome (PWS) and Angelman syndrome (AS). Here we describe two unrelated PWS patients with a typical deletion, whose fathers have a balanced translocation involving the PWS/AS region. Microsatellite data suggest that the deletion is the result of an unequal crossover between the derivative chromosome 15 and the normal chromosome 15. We conclude that familial translocations involving 15q11-q13 can give rise to interstitial deletions causing PWS or AS and that prenatal diagnosis in such families should include fluorescence in situ hybridisation or microsatellite studies or both. %U https://jmg.bmj.com/content/jmedgenet/33/10/848.full.pdf