Balanced reciprocal translocation mosaicism: how frequent?
We describe 2 cases of balanced reciprocal translocation (BRT) mosaicism. The frequency of this aberration in the population referred to our laboratory was determined and compared to those frequencies reported in the literature by other clinical cytogenetics laboratories. The extent of BRT mosaicism was also examined in surveys of parental populations, which are less likely to have a bias due to ascertainment on the basis of abnormal phenotype. the frequencies in the postnatal and prenatal populations examined in this study were calculated to be 5.7 x 10(-5) (95% confidence interval is 3.2-8.2 x 10(-5)) and 4.1 x 10(-5) (95% confidence interval is 2.0-6.2 x 10(-5)). However, in view of the extent of variation reported in the various studies, these estimates should be considered first approximations of the true frequency.
Opheim
K E
KE
Department of Pathology, University of Washington, Seattle 98195, USA.
Brittingham
A
A
Chapman
D
D
Norwood
T H
TH
D000015:Abnormalities, Multiple / Q000235:genetics; D005315:Fetal Diseases / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007621:Karyotyping; D009030:Mosaicism / Q000235:genetics*; D011159:Population Surveillance; D014178:Translocation, Genetic