Bondy Carolyn A, Hougen Helen Y, Zhou Jian, Cheng Clara M
Section on Epigenetics & Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Pediatr Endocrinol Rev. 2012 May;9 Suppl 2:728-32.
The term 'genomic imprinting' refers to selective repression of transcription from distinct chromosomal regions determined by their maternal or paternal inheritance. There are two potentially important aspects of imprinting that may manifest in individuals with X monosomy, or Turner syndrome (TS). Given that men are monosomic for Xm while women are mosaic for Xm:Xp, genomic imprinting of important X-linked genes should be associated with sexually dimorphic traits, e.g., social skills, regional fat deposition and adult height. Such X-imprinted traits are predicted to differ in Turner groups monosomic for Xm vs. Xp. We review relevant studies of psychosocial attributes, regional fat distribution and height in TS related to parent of origin for the single normal X chromosome. In addition, we review recent evidence that monosomy for the X chromosome per se, regardless of the parental origin, may disrupt the normal distribution of autosomal imprint patterns. This may contribute to a high rate of fetal loss in human monosomy via impaired placentation in the most severe cases, and to loss of paternal contribution to growth in the mildest manifestation.
“基因组印记”一词指的是由染色体的母系或父系遗传决定的不同染色体区域转录的选择性抑制。印记有两个潜在的重要方面，可能在X单体或特纳综合征（TS）个体中表现出来。鉴于男性为Xm单体，而女性为Xm:Xp嵌合体，重要的X连锁基因的基因组印记应与性别二态性特征相关，例如社交技能、局部脂肪沉积和成年身高。预计此类X印记性状在Xm单体与Xp单体的特纳组中会有所不同。我们回顾了与单一正常X染色体的亲本来源相关的TS患者心理社会属性、局部脂肪分布和身高的相关研究。此外，我们回顾了最近的证据，即无论亲本来源如何，X染色体单体本身可能会破坏常染色体印记模式的正常分布。在最严重的情况下，这可能会导致人类单体胎儿的高流产率，在最轻微的表现中，这可能会导致父系对生长的贡献丧失。
