Kaiser-Rogers K A, McFadden D E, Livasy C A, Dansereau J, Jiang R, Knops J F, Lefebvre L, Rao K W, Robinson W P
J Med Genet. 2006 Feb;43(2):187-92. doi: 10.1136/jmg.2005.033571. Epub 2005 May 20.
Placental mesenchymal dysplasia (PMD) is a distinct syndrome of unknown aetiology that is associated with significant fetal morbidity and mortality. Intrauterine growth restriction is common, yet, paradoxically, many of the associated fetuses/newborns have been diagnosed with Beckwith-Wiedemann syndrome (BWS).
We report two cases of PMD with high levels of androgenetic (complete paternal uniparental isodisomy) cells in the placenta and document, in one case, a likely androgenetic contribution to the fetus as well.
The same haploid paternal complement found in the androgenetic cells was present in coexisting biparental cells, suggesting origin from a single fertilisation event.
Preferential allocation of the normal cells into the trophoblast explains the absence of trophoblast overgrowth, a key feature of this syndrome. Interestingly, the distribution of androgenetic cells appears to differ from that reported for artificially created androgenetic mouse chimeras. Androgenetic mosaicism for the first time provides an aetiology for PMD, and may be a novel mechanism for BWS and unexplained intrauterine growth restriction.
胎盘间充质发育异常（PMD）是一种病因不明的独特综合征，与胎儿显著的发病率和死亡率相关。宫内生长受限很常见，但矛盾的是，许多相关胎儿/新生儿被诊断为贝克威思-维德曼综合征（BWS）。
我们报告了两例胎盘中有高水平单亲二倍体（完全父源单亲二体）细胞的PMD病例，并在其中一例中记录了可能对胎儿也存在的单亲二倍体影响。
在单亲二倍体细胞中发现的相同单倍体父源互补存在于共存的双亲细胞中，提示起源于单一受精事件。
正常细胞优先分配到滋养层解释了滋养层过度生长的缺失，这是该综合征的一个关键特征。有趣的是，单亲二倍体细胞的分布似乎与人工创建的单亲二倍体小鼠嵌合体的报道不同。单亲二倍体嵌合体首次为PMD提供了病因，可能是BWS和不明原因宫内生长受限的一种新机制。
