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A 48,XXY,+21 Down syndrome patient with additional paternal X and maternal 21
I Lorda-Sanchez1, M B Petersen, F Binkert
1Institut für Medizinische Genetik der Universität, Zürich, Switzerland.
Human Genetics
|May 1, 1991
Abstract:
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.