A NEW GENETIC CONCEPT - UNIPARENTAL DISOMY AND ITS POTENTIAL EFFECT, ISODISOMY
A NEW GENETIC CONCEPT - UNIPARENTAL DISOMY AND ITS POTENTIAL EFFECT, ISODISOMY
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DOI：
10.1002/ajmg.1320060207
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发表时间：
1980-01-01
期刊：
影响因子：
--
通讯作者：
ENGEL, E
中科院分区：
文献类型：
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作者：
ENGEL, E
近年来，对自然流产产品的细胞遗传学研究表明，非整倍体胚胎的频率相对较高。这些核型异常主要源于减数分裂错误，影响了染色体在两个配子中的一个的分布。这一信息不仅意味着生殖细胞非整倍体的显着频率，而且还揭示了某些类型错误的流行。因此，配子的单倍体往往会因某些成员的缺失(缺体)或增加(二体)而改变，特别是X、Y和15、16、21和22号染色体。因此，在一些特殊的合子中，可以预料到，在一些特殊的受精卵中，整倍体可能是由二体配子与同源配子的缺体随机结合而产生的。对于这一假设现象--然而，从统计上讲是可能的，也是可以预见的--我们将其命名为近亲二体，因为这样的一对中的两个成员都只来自一个父母。此外，这种机制意味着将具有相同等位基因的完整序列的染色体引入基因组对的可能性，这一结果我们用同体的新词来描述。一系列共线等位基因的这种纯合性从遗传角度来看，意味着类似于亲缘关系的风险和优势。类似的机制也可以调节和修改三体的后果，在三体中，三条相关染色体中的两条染色体的整个片段，包括额外的一条，也可以是等位的(等二体三肌等三体)。本文简要阐述了源于单亲二体概念的其他一些预测，这些预测的证实应该作为对所提出的假设的检验。
In recent years, cytogenetic studies of spontaneous abortion products have disclosed a relatively high frequency of aneuploid embryos. These karyotypic anomalies chiefly stem from meiotic errors affecting the distribution of the chromosomes in one of the two gametes. This information not only implies the remarkable frequency of gonocyte aneuploidy but also reveals the prevalence of certain types of errors. It follows that gametal haploidy is often altered by the loss (nullisomy) or the addition (disomy) of certain members, in particular the X, the Y, and chromosomes 15, 16, 21, and 22.Therefore, it is to be expected that, in some exceptional zygotes, euploidy could result from the random union of a disomic gamete with a gamete nullisomic for the homologue. To this hypothetical phenomenon ‐ which is, however, statistically likely and foreseeable ‐ we have ascribed the name ofuniparental disomy, owing to the fact that both members of such a pair arise from only one parent. Furthermore, such a mechanism implies the probability of introducing into the genome pairs of chromosomes with whole sequences of identical alleles, a consequence which we describe by the neologism ofisodisomy. Such homozygosity for a series of colinear alleles implies, from the genetic stand‐point, risks and advantages akin to those of parental consanguinity.An analogous mechanism could also modulate and modify the consequences of trisomies in which entire segments of two of the three implicated chromosomes, including the supernumerary one, could as well be isoallelic (isodisomic trisomyordi‐isotrisomy). This article briefly states some other predictions stemming from the concept of uniparental disomy, whose confirmation should serve as a test of the proposed hypothesis.