2008 Barcelona - European Society of Human Genetics

Cytogenetics
did not influence upon their background frequency of chromosome
aberrations . Under joint incubation of X-irradiated in vitro (in doses
250 and 1000 mGy) and intact lymphocytes the dose-dependent interaction
between targeted and untargeted cells had been discovered
- cytogenetic effect in bystander cells (4 .31 and 6 .13 of aberrations
per 100 metaphases, accordingly) cultivated with irradiated ones (6 .99
and 21 .19 of aberrations per 100 metaphases, accordingly) elevated
their background level (2 .27 aberrations per 100 metaphases) . In
mixed cultures established from unexposed donors and Chernobyl
liquidators (with radiation doses in range 1010-2370 mGy) the meangroup
frequencies of aberrations in irradiated cells were 5 .21±0 .89 per
100 metaphases, in bystander cells - 4 .05±0 .64 per 100 metaphases .
The difference between spectrum of aberrations in exposed and intact
cells had been revealed both in vitro and in vivo - in targeted cells
specific cytogenetic markers of irradiation dominated (unstable and
stable chromosome exchanges), as well as in “bystander” cells simple
aberrations (chromatid breaks and terminal deletions that can be consider
as the markers of chromosome instability) mainly induced . All
cytogenetic effects had been characterized by essential interindividual
fluctuations.
P02.187
can segregation analysis in spermatozoa of male carriers of a
reciprocal translocation help in genetic counselling?
E. Van Assche 1 , W. Vegetti 2 , M. Bonduelle 3 , G. Verheyen 4 , A. Van Steirteghem
4 , I. Liebaers 3 ;
1 Center for Medical Genetics- UZA, Antwerp, Belgium, 2 First Department of
Obstetrics and Gyneacology, Milan, Italy, 3 Center for Medical Genetics UZ-
Brussel, Brussels, Belgium, 4 Center for Reproductive Medicine UZ-Brussel,
Brussels, Belgium.
Balanced reciprocal translocations (Rcp), the most frequent chromosomal
rearrangements in humans are mainly transmitted by one of the
parents . We used the FISH technique to analyse the chromosomal
content of spermatozoa from 20 Rcp carriers . A total of 15375 sperm
nuclei were analysed . The mean frequency of normal/balanced and
unbalanced gametes in the carriers was 47 .4% (range 20 .4-89 .6%)
and 52 .6% respectively . In 11/20 carriers the frequency of normal/balanced
and unbalanced sperm differed statistically (p