Magee A C, Nevin N C, Armstrong M J, McGibbon D, Nevin J
Regional Genetic Service, Belfast City Hospital Trust, United Kingdom.
Am J Med Genet. 1998 Jan 6;75(1):1-3.
A 37-year-old woman was referred for genetic counseling after termination of her probable seventh pregnancy. Ultrasound examination at 13 weeks of gestation had shown a fetus with bilateral cystic hygromas. A transabdominal amniocentesis confirmed 45,X karyotype in the fetus. The patient had marked short stature and a 45,X chromosome constitution in blood lymphocytes. Subsequently she had a hysterectomy and oophorectomy. Tissue of representative sites of the pathological specimen showed a 45,X chromosome constitution. However, molecular analysis of 8 sites from the uterus and ovaries, and of skin fibroblasts with X-chromosome microsatellites showed the presence of only one allele, except for the microsatellite DXS996 which demonstrated 2 alleles (155 bp and 161 bp) in ovarian tissue. The lymphocytes from the mother and her only son demonstrated the same single allele (161 bp). We conclude that molecular analysis of lymphocytes and of tissue is necessary for detecting low-level mosaicism in apparently homogeneous 45,X women.
一名37岁女性在终止其可能的第七次妊娠后前来接受遗传咨询。妊娠13周时的超声检查显示胎儿双侧有囊性水瘤。经腹羊膜腔穿刺术证实胎儿核型为45,X。该患者身材明显矮小，血液淋巴细胞的染色体组成为45,X。随后她接受了子宫切除术和卵巢切除术。病理标本代表性部位的组织显示为45,X染色体组成。然而，对子宫、卵巢的8个位点以及皮肤成纤维细胞进行X染色体微卫星分子分析发现，除卵巢组织中的微卫星DXS996显示有两个等位基因（155 bp和161 bp）外，其余仅存在一个等位基因。母亲及其独子的淋巴细胞显示相同的单等位基因（161 bp）。我们得出结论，对于表面上均一的45,X女性，进行淋巴细胞和组织的分子分析对于检测低水平嵌合体是必要的。
