Many Prader-Willi syndrome (PWS) and Angelman syndrome (AS) patients have a 
cytogenetic deletion of 15q11q13. While AS and PWS share a similar cytogenetic 
anomaly, they have very different clinical phenotypes. DNAs from 4 AS patients 
were examined using 5 chromosome 15q11q13-specific cloned DNA segments. With the 
present level of resolution, the molecular deletions between AS and those 
previously reported for PWS did not appear to differ. However, in contrast to 
the paternal inheritance of the deleted chromosome 15 observed in the majority 
of PWS patients, maternal inheritance of the deleted chromosome 15 was 
demonstrated in the AS patients by restriction fragment length polymorphisms 
(RFLPs).