Hynd Thomas E, Buckley Cadie L, Lozanoff Scott
Department of Anatomy, Biochemistry and Physiology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA.
Birth Defects Res A Clin Mol Teratol. 2013 Jun;97(6):421-4. doi: 10.1002/bdra.23151. Epub 2013 Jun 13.
Cephalothoracopagus twinning is extremely rare, and it is characterized by fusion of the head and thorax, two separate spines, pelves, and fore- and hindlimbs.
In this case study, we describe cephalothoracopagus twinning in an embryonic mouse displaying a large but exencephalic head, median facial cleft, a single eye, and a second hindbrain rotated roughly 90° from a second spinal cord. There is a bony connection joining the clavicles, resulting in merged asternal thoracic cavities containing two hearts and four lungs. The abdominal cavities contain double caudal digestive tract structures, but a single esophagus and stomach.
There are several proposed theories regarding the mechanism of spontaneous conjoined twinning; however, the specific mechanisms are still largely unknown. In this report, we highlight the morphological features in a murine example of cephalothoracopagus twinning, furthering our understanding of this rare occurrence while also demonstrating developmental morphogenesis consistent with that reported for human conjoined twins.
头胸联体双胎极为罕见，其特征为头部与胸部融合，有两根独立的脊柱、骨盆以及前肢和后肢。
在本病例研究中，我们描述了一只胚胎小鼠的头胸联体双胎情况，该小鼠头部较大但无脑，面部正中裂，单眼，且第二个后脑相对于第二根脊髓大致旋转了90°。有一个骨性连接连接着锁骨，导致合并的无胸骨胸腔内有两颗心脏和四个肺。腹腔内有双尾消化道结构，但食管和胃为单个。
关于自然联体双胎的机制有几种提出的理论；然而，具体机制在很大程度上仍然未知。在本报告中，我们突出了头胸联体双胎小鼠实例中的形态学特征，增进了我们对这种罕见情况的理解，同时也展示了与人类联体双胎报道一致的发育形态发生过程。
