Barasoain Maitane, Barrenetxea Gorka, Huerta Iratxe, Télez Mercedes, Criado Begoña, Arrieta Isabel
Department of Genetics, Physical Anthropology and Animal physiology, Faculty of Science and Technology, University of the Basque Country, Bilbao, 48940, Spain.
Department of Medical-Surgical Specialities, Faculty of Medicine, University of the Basque Country, Bilbao, 48940, Spain.
Genes (Basel). 2016 Dec 13;7(12):123. doi: 10.3390/genes7120123.
Menopause is a period of women's life characterized by the cessation of menses in a definitive way. The mean age for menopause is approximately 51 years. Primary ovarian insufficiency (POI) refers to ovarian dysfunction defined as irregular menses and elevated gonadotrophin levels before or at the age of 40 years. The etiology of POI is unknown but several genes have been reported as being of significance. The gene () is one of the most important genes associated with POI. The gene contains a highly polymorphic CGG repeat in the 5' untranslated region of exon 1. Four allelic forms have been defined with respect to CGG repeat length and instability during transmission. Normal (5-44 CGG) alleles are usually transmitted from parent to offspring in a stable manner. The full mutation form consists of over 200 repeats, which induces hypermethylation of the gene promoter and the subsequent silencing of the gene, associated with Fragile X Syndrome (FXS). Finally, intermediate (45-54 CGG) and premutation (55-200 CGG) alleles have been principally associated with two phenotypes, fragile X tremor ataxia syndrome (FXTAS) and fragile X primary ovarian insufficiency (FXPOI).
更年期是女性生命中的一个阶段，其特征是月经最终停止。更年期的平均年龄约为51岁。原发性卵巢功能不全（POI）是指卵巢功能障碍，定义为40岁之前或40岁时月经不规律且促性腺激素水平升高。POI的病因尚不清楚，但已有多个基因被报道具有重要意义。 基因（）是与POI相关的最重要基因之一。该基因在第1外显子的5'非翻译区含有高度多态性的CGG重复序列。已根据CGG重复序列长度和传递过程中的不稳定性定义了四种等位基因形式。正常（5 - 44个CGG）等位基因通常以稳定的方式从亲代传递给后代。完全突变形式由超过200个重复序列组成，这会导致该基因启动子的高甲基化以及随后该基因的沉默，与脆性X综合征（FXS）相关。最后，中间型（45 - 54个CGG）和前突变型（55 - 200个CGG）等位基因主要与两种表型相关，即脆性X震颤共济失调综合征（FXTAS）和脆性X原发性卵巢功能不全（FXPOI）。
