Summary
Interstitial cytogenetic deletions involving the paternally derived chromosome 15q11–13 have been described in patients with the Prader-Willi syndrome (PWS). We report a child with PWS and a de novo unbalanced karyotype −45,XY,−9,−15,+der(9)t(9;15)(q34;q13). Molecular studies with the DNA probe pML34 confirmed that only a single Prader Willi critical region (PWCR: 15q11.2-q12) copy was present. Hybridisation of patient and parental DNA with the multi-allelic probe CMW1, which maps to pter-15q13, showed that the chromosome involved in the translocation was paternal in origin. This is the first example of a paternally-derived PWCR allele loss caused by an unbalanced translocation that has arisen de novo.
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Smith, A., Lindeman, R., Volpato, F. et al. A de novo unbalanced reciprocal translocation identified as paternal in origin in the Prader-Willi syndrome. Hum Genet 86, 534–536 (1991). https://doi.org/10.1007/BF00194651
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DOI: https://doi.org/10.1007/BF00194651