Department of Psychobiology, University of A Coruña, Campus Elviña, A Coruña, Spain.
Horm Res Paediatr. 2010;73(3):210-4. doi: 10.1159/000284364. Epub 2010 Mar 3.
Turner's syndrome, also known as 'monosomy X', is a genetic disorder that occurs in 1/2,500 female births and is hypothesized to result from haploinsufficiency of certain genes expressed from both sex chromosomes that escape X inactivation. While the classic karyotype related to Turner's syndrome is 45,X, the majority of those affected actually have a mosaic chromosomal complement, most often with a second normal cell line (46,XX). The resulting phenotype is variable and related to the underlying chromosomal pattern, but it is characterized by three cardinal features: short stature (around 100%), ovarian failure (>90%) and congenital lymphedema (>80%). In this paper we report a molecular and cytogenetic investigation of a 26-year-old female with non-mosaic 45,X karyotype, who has a stature of 170 cm without GH treatment, and whose only apparent Turner feature is gonadal dysgenesis. The only possible explanation for the absence of Turner phenotype is the hidden mosaicism combined with an untreated gonadal dysgenesis. Our results support the theory that significant ascertainment bias exists in our understanding of Turner's syndrome.
特纳综合征，又称“单体 X 综合征”，是一种遗传疾病，在 2500 名女性出生中发生 1 例，据推测是由于来自两条性染色体的某些基因表达的单倍体功能不全，而这些基因逃避了 X 染色体失活。虽然与特纳综合征相关的经典核型为 45,X，但大多数受影响的个体实际上具有镶嵌染色体组成，最常见的是第二种正常细胞系（46,XX）。由此产生的表型是可变的，并与潜在的染色体模式相关，但它的特征是三个主要特征：身材矮小（约 100%）、卵巢功能衰竭（>90%）和先天性淋巴水肿（>80%）。在本文中，我们报告了对一名 26 岁女性的分子和细胞遗传学研究，该女性具有非镶嵌性 45,X 核型，未经 GH 治疗，身高为 170cm，唯一明显的特纳综合征特征是性腺发育不良。特纳表型缺失的唯一可能解释是隐匿性镶嵌性与未经治疗的性腺发育不良相结合。我们的结果支持这样一种理论，即特纳综合征的认识存在显著的选择偏差。
