A case of mosaic Down's syndrome with two Robertsonian translocations.
A baby with stigmata of Down's syndrome was found to be a mosaic with two different cell lines: 45,XX,der(14q;21q)/46,XX,der(21q;21q)+21. The chromosome rearrangements appeared to have risen de novo. Four mechanisms are discussed for the origin of the mosaicism: dissociation of a translocation (14q;21q) chromosome already present in the 45,XX, der(14q;21q) zygote; two translocation events occurring sequentially at the first and second zygote (46,XX) divisions; a chromatid translocation in a 47,XX,+21 zygote; and an independent origin of the two cell lines.
Leal-Garza
C H
CH
Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey N.L. México.
Cortés-Gutiérrez
E I
EI
Ortiz-Jalomo
R
R
García-Cavazos
R
R
D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D009030:Mosaicism / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*