Susceptible chiasmate configurations of chromosome 21 predispose to non–disjunction in both maternal meiosis I and meiosis II
| Autor: | Michael B. Petersen, Sallie B. Freeman, Anni Hallberg, Yuanchao Gu, Terry J. Hassold, Stephanie L. Sherman, Denise Saker, Margareta Mikkelsen, Dorothy Pettay, Dimitris Avramopoulos, Kristen M. May, Neil E. Lamb, Joseph J. Shen, Amanda Savage-Austin, Jane Hersey, Lisa Taft |
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| Rok vydání: | 1996 |
| Předmět: |
Adult
Male Chromosomes Human Pair 21 Aneuploidy Biology Genetic recombination Fetus Nondisjunction Genetic Meiosis Genetics medicine Humans reproductive and urinary physiology Recombination Genetic Models Genetic urogenital system Meiosis II Embryo Mammalian medicine.disease Chiasma Nondisjunction embryonic structures Female Down Syndrome Trisomy Chromosome 21 Maternal Age |
| Zdroj: | Nature Genetics. 14:400-405 |
| ISSN: | 1546-1718 1061-4036 |
| DOI: | 10.1038/ng1296-400 |
| Popis: | The cause of non-disjunction of chromosome 21 remains largely unknown. Advanced maternal age is associated with both maternal meiosis I (MI) and meiosis II (MII) non-disjunction events. While reduced genetic recombination has been demonstrated in maternal MI errors, the basis for MII errors remains uncertain. We studied 133 trisomy 21 cases with maternal MII errors to test the hypothesis that segregation at MII may also be influenced by genetic recombination. Our data support a highly significant association: MII non-disjunction involves increased recombination that is largely restricted to proximal 21q. Thus, while absence of a proximal recombination appears to predispose to non-disjunction in MI, the presence of a proximal exchange predisposes to non-disjunction in MII. These findings profoundly affect our understanding of trisomy 21 as they suggest that virtually all maternal non-disjunction results from events occurring in meiosis I. |
| Databáze: | OpenAIRE |
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