[Chromosome aberrations in Prader-Willi-Labhart syndrome--critical review, documented by 4 unusual cases]

Report on two males who exhibit a syndrome which reminds Prader-Willi-Labhart syndrome (PWLS) because of craniofacial dysmorphy, acromicria, hypogenitalism, obesity and mental deficiency. A supernumerary small marker chromosome was identified as duplication of the juxtameric parts of chromosome 15. In a 15 years old female and in a 4 years old unrelated male deletion of 15q1 is due to translocation with a chromosome 7 and 20 respectively subsequent to 3:1 distribution. Therefore both patients share partial monosomies of chromosome 15 but also of the other autosome involved. Various chromosomal aberrations in PWLS but mostly deletions of chromosome 15 either isolated or associated with translocation are summarized. Patients with a PWLS like syndrome and a marker chromosome consisting of juxtameric parts of chromosome 15 constitute a particular group which is delineated from PWLS but also from a large heterogeneous group of supernumerary marker chromosomes.