Veenema H, Geraedts J P, Beverstock G C, Pearson P L
J Med Genet. 1987 Jan;24(1):23-31. doi: 10.1136/jmg.24.1.23.
Cytogenetic and clinical investigations were performed in 85 members of a large family, in which 18 males and seven females were mentally retarded. In the male patients the fragile site Xq27 was found in 6 to 44% (mean 22.5%) of peripheral blood lymphocytes. One non-retarded male expressed the cytogenetic abnormality in 6% of his cells. In 21 females the fra(X) was found in 3 to 28% (mean 8.7%) of their cells. Two obligate carriers did not express the fragile site. A significant difference in expression between the seven retarded (mean 16.7%) and seven non-retarded female carriers of corresponding age (mean 6.3%) was found (alpha = 0.01). No significant correlation between expression and age could be established, either in males or in females. The cytogenetic results appeared to be consistent. To avoid false positives, a cut-off point was chosen: males were considered to be fra(X) negative if no more than one in 100 cells showed the abnormality; for females the cut-off point was two in 100 cells. Segregation analysis did not detect significant deviations from the expected ratios. The putative presence of a transmitting male is discussed. The results of recombinant DNA analysis will be published elsewhere. Clinical investigations confirmed the findings of others. CT scans showed an enlargement of the ventricular system that exceeded the expected age changes.
对一个大家庭的85名成员进行了细胞遗传学和临床研究，其中18名男性和7名女性智力发育迟缓。在男性患者中，外周血淋巴细胞中发现脆性位点Xq27的比例为6%至44%（平均22.5%）。一名智力正常的男性在其6%的细胞中表现出细胞遗传学异常。在21名女性中，其细胞中发现fra(X)的比例为3%至28%（平均8.7%）。两名肯定携带者未表现出脆性位点。在7名智力发育迟缓的女性携带者（平均16.7%）和7名年龄相仿的智力正常的女性携带者（平均6.3%）之间发现了表达上的显著差异（α = 0.01）。在男性或女性中，均未发现表达与年龄之间存在显著相关性。细胞遗传学结果似乎是一致的。为避免假阳性，选择了一个临界点：如果每100个细胞中显示异常的细胞不超过1个，则男性被认为是fra(X)阴性；对于女性，临界点是每100个细胞中有2个。分离分析未检测到与预期比例的显著偏差。讨论了可能存在的传递男性。重组DNA分析的结果将在其他地方发表。临床研究证实了其他人的发现。CT扫描显示脑室系统扩大，超出了预期的年龄变化。
