Sister chromatid exchange in families with Angelman or Prader‐Willi syndrome

Abstract

Using estimation of numbers of sister chromatid exchanges arising in 15q 11 q 13 as a measure, comparisons of the stability of the Prader‐Willi syndrome critical region have been made. The groups studied included probands with Prader‐Willi or Angelman syndromes either with or without a cytogenetically visible deletion in 15q11q13, their parents, specifically those parents who had passed on the homologue which had become deleted, and a control group. No significant differences were found between any of the four groups, indicating that there was no increase in the instability of the PWSCR region as measured by sister chromatid exchange.

Sister chromatid exchange in Prader‐Willi syndrome families

“…Compilation of data from both tables shows that about 5.5% of SCE on the #I5 chromosomes occurred at 15ql1 for both fathers and mothers. These findings concur with those reported by Webb (1994) and Butler & Jenkins (1989), suggesting that there may be no increased susceptibility to breakage in this region for specific individuals, at least as measured by these cytogenetic techniques. Comparison between mothers and fathers by x2 goodness of fit was not significantly different (df=5; x2=3.40; ~~0 .…”

“…To the Editor: Webb (1994) recently published the results of sister chromatid exchange (SCE) occurring on chromosome 15 in Prader-Willi syndrome (PWS) and Angelman syndrome (AS) patients and their parents. She found no increase in SCE within the proximal 15q for the parental 15 homolog inherited as a deletion in the affected child, corresponding to the finding in PWS families by Butler & Jenkins (1989).…”