Genetics 21
نویسنده
چکیده
Introduction The estimation of genetic risks to the offspring of consanguineous marriages, especially those of first cousins, has been exhaustively studied in the literature. Even so the subject still remains controversial, as shown by the results of a recent inquiry performed among medical geneticists and genetic counsellors in the United States by Bennett et al. (1999). In fact, analysing the answers they received from 309 professionals, these authors showed that the risks of genetic disease given by these professionals to first-cousin couples ranged from 0.5% to 20% and that there was no consensus as to the types of defects and diseases they included in the calculation of these risks.
منابع مشابه
A giant short arm of no. 21 chromosome in mother of 21/21 translocation mongol.
An extreme variation of the short arm of no. 21 chromosome in the mother of a 21/21 translocation mongol is described. The possible relation between the very long short arm of chromosome no. 21 in the mother and a centric fusion type of translocation mongolism in the offspring is discussed.
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Chromosome 21 is the smallest autosome, comprising only about 1.9% of human DNA, but represents one of the most intensively studied regions of the genome. Much of the interest in chromosome 21 can be attributed to its association with Down's syndrome, a genetic disorder that afflicts one in every 700 to 1000 newborns. Although only 17 genes have been assigned to chromosome 21, a very large numb...
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The occurrence of 46,XX/47,XX,+21 mosaicism in two successive generations implies an aetiological relationship between the 47,XX,+21 cell line of the mother and her daughter.
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