M. Schliephacke et al., THE EVALUATION OF GONOSOMAL MOSAICS - LYMPHOCYTE INTERPHASE NUCLEI ANALYZED BY FISH, Clinical genetics, 50(2), 1996, pp. 99-102
The reliable evaluation of chromosomal mosaics is still considered to
be difficult in clinical diagnosis if aberrant metaphases are only pre
sent at low frequencies. Classical cytogenetic findings cannot signifi
cantly exclude low mosaic levels, obviously, because of the relatively
low number of analyzed metaphases. To study this problem, the number
of gonosomes in lymphocyte interphase nuclei was determined by FISH (f
luorescence in situ hybridization) application of two satellite DNA pr
obes, DXZ1 and DYZ1. The results obtained with this method from lympho
cytes of clinically and cytogenetically inconspicuous persons showed a
high degree of reliability. The DNA probe yielded correct signals in
more than 95% of the analyzed nuclei. Additionally, patients were exam
ined who showed cytogenetically confirmed numerical gonosome aberratio
ns. These results were compared with those obtained from the control g
roup of inconspicuous patients and discussed with respect to the evalu
ation of gonosomal mosaics.