Investigations with fluorescence in situ hybridization (FISH) demonstrate loss of the telomeres on the reciprocal chromosome in three unbalanced translocations involving chromosome 15 in the Prader-Willi and Angelman syndromes.
Two patients with classical features of Angel-man syndrome (AS) and one with Prader-Willi syndrome (PWS) had unbalanced reciprocal translocations involving the chromosome 15 proximal long arm and the telomeric region of chromosomes 7, 8 and 10. Fluorescence in situ hybridization (FISH) was used for the detection of chromosome 15(q11-13) deletions (with probes from the PWS/AS region) and to define the involvement of the telomere in the derivative chromosomes (with library probes and telomere-specific probes). The 15(q11-13) region was not deleted in one patient but was deleted in the other two. The telomere on the derivative chromosomes 7, 8 and 10 was deleted in all three cases. Thus, these are true reciprocal translocations in which there has been loss of the small satellited reciprocal chromosome (15) fragment.
Jauch
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A
Institut für Humangenetik und Anthropologie, Universität Heidelberg, Germany.
Robson
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L
Smith
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A
D000328:Adult; D017204:Angelman Syndrome / Q000235:genetics*; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D015342:DNA Probes; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D011218:Prader-Willi Syndrome / Q000235:genetics*; D016615:Telomere / Q000235:genetics* / Q000378:metabolism; D014178:Translocation, Genetic / Q000235:genetics*
D015342:DNA Probes