nondisjunction in man . predisposition to Possible evidence for genetic
نویسنده
چکیده
SIR, As discussed in our paper (J Med Genet 1987;24: 52-9) and in the comments by Dr Harris, the number of cases available for obtaining risk figures is very small and inadequate. Furthermore, there is considerable variability between the results of various studies. Statistical tests may not be appropriate until a larger sample size is available. Although the statistical analysis does not show a clear difference in risk for families with and without
منابع مشابه
Lack of evidence for association of meiotic nondisjunction with particular DNA haplotypes on chromosome 21.
The hypothesis of a predisposition to meiotic nondisjunction for chromosome 21 carrying a specific molecular haplotype has been tested. The haplotype in question is defined by the restriction fragment length polymorphisms for the D21S1/D21S11 loci. Our results obtained on a sample of Northern Italian families with the occurrence of trisomy 21 (Down syndrome) failed to support this hypothesis, c...
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Meiotic nondisjunction can be induced by external agents, such as heat, radiation, and chemicals, and by internal genotypic alterations, namely, point mutations and chromosomal rearrangements. In many cases, nondisjunction arises from a reduction or elimination of crossing over, leading to the production of homologous univalents which fail to co-orient on the metaphase plate and to disjoin prop...
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تاریخ انتشار 2004