A 48,XXY,+21 Down syndrome patient with additional paternal X and maternal 21.
The origin of meiotic nondisjunction of the extra chromosomes X and 21 was studied in a patient with the karyotype 48,XXY,+21 using DNA polymorphisms. The extra chromosome X was the result of paternal first meiotic nondisjunction of X and Y. The extra chromosome 21 was derived from the mother. The meiotic error in the mother most probably occurred in meiosis II. Thus, this is a combination caused by the chance occurrence of two independent events.
Institut für Medizinische Genetik der Universität, Zürich, Switzerland.
I
I
Lorda-Sanchez
M B
MB
Petersen
F
F
Binkert
M
M
Maechler
W
W
Schmid
P A
PA
Adelsberger
S E
SE
Antonarakis
A
A
Schinzel
D000782:Aneuploidy; D001345:Autoradiography; D015139:Blotting, Southern; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D007713:Klinefelter Syndrome / Q000235:genetics*; D008297:Male; D012150:Polymorphism, Restriction Fragment Length; D014960:X Chromosome