Álvarez-Nava Francisco, Soto-Quintana Marisol
Biological Sciences School, Faculty of Biological Sciences, Central University of Ecuador, Quito 170113, Ecuador.
Genetic Research Institute, University of Zulia, Maracaibo 4001, Venezuela.
J Dev Biol. 2022 May 11;10(2):16. doi: 10.3390/jdb10020016.
Turner syndrome (TS) is a chromosomal disorder that is caused by a missing or structurally abnormal second sex chromosome. Subjects with TS are at an increased risk of developing intrauterine growth retardation, low birth weight, short stature, congenital heart diseases, infertility, obesity, dyslipidemia, hypertension, insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and cardiovascular diseases (stroke and myocardial infarction). The underlying pathogenetic mechanism of TS is unknown. The assumption that X chromosome-linked gene haploinsufficiency is associated with the TS phenotype is questioned since such genes have not been identified. Thus, other pathogenic mechanisms have been suggested to explain this phenotype. Morphogenesis encompasses a series of events that includes cell division, the production of migratory precursors and their progeny, differentiation, programmed cell death, and integration into organs and systems. The precise control of the growth and differentiation of cells is essential for normal development. The cell cycle frequency and the number of proliferating cells are essential in cell growth. 45,X cells have a failure to proliferate at a normal rate, leading to a decreased cell number in a given tissue during organogenesis. A convergence of data indicates an association between a prolonged cell cycle and the phenotypical features in Turner syndrome. This review aims to examine old and new findings concerning the relationship between a prolonged cell cycle and TS phenotype. These studies reveal a diversity of phenotypic features in TS that could be explained by reduced cell proliferation. The implications of this hypothesis for our understanding of the TS phenotype and its pathogenesis are discussed. It is not surprising that 45,X monosomy leads to cellular growth pathway dysregulation with profound deleterious effects on both embryonic and later stages of development. The prolonged cell cycle could represent the beginning of the pathogenesis of TS, leading to a series of phenotypic consequences in embryonic/fetal, neonatal, pediatric, adolescence, and adulthood life.
特纳综合征（TS）是一种染色体疾病，由第二条性染色体缺失或结构异常引起。患有TS的个体发生宫内生长迟缓、低出生体重、身材矮小、先天性心脏病、不孕不育、肥胖、血脂异常、高血压、胰岛素抵抗、2型糖尿病、代谢综合征以及心血管疾病（中风和心肌梗死）的风险增加。TS的潜在发病机制尚不清楚。由于尚未鉴定出此类基因，因此有人对X染色体连锁基因单倍剂量不足与TS表型相关的假设提出了质疑。因此，人们提出了其他致病机制来解释这种表型。形态发生包括一系列事件，包括细胞分裂、迁移前体及其后代的产生、分化、程序性细胞死亡以及整合到器官和系统中。细胞生长和分化的精确控制对于正常发育至关重要。细胞周期频率和增殖细胞数量在细胞生长中至关重要。45,X细胞无法以正常速率增殖，导致器官发生过程中给定组织中的细胞数量减少。数据的汇集表明细胞周期延长与特纳综合征的表型特征之间存在关联。本综述旨在研究有关细胞周期延长与TS表型之间关系的新旧发现。这些研究揭示了TS中多种表型特征，这些特征可以用细胞增殖减少来解释。讨论了这一假设对我们理解TS表型及其发病机制的意义。45,X单体导致细胞生长途径失调，对胚胎发育和后期发育产生深远的有害影响，这并不奇怪。延长的细胞周期可能代表了TS发病机制的开始，导致在胚胎/胎儿、新生儿、儿童、青少年和成年期出现一系列表型后果。
