脆性X综合征的细胞遗传学及临床研究

A STUDY OF FRAGILE X SYNDROME IN CYTOGENETICS AND CLINICAL CHARACTERISTICS

采用TC109加FUdR诱导Fra(X)的方法,共检测先天性智力低下儿童140名,发现10名脆性X综合征患者。在140名智低儿童中122名来自弱智学校,其脆性X综合征患病率为5.7%(7/122)。对4例先证者进行家系调查,检出了5例Fra(X)阳性患者及4例女性携带者。在女性杂合子中对活性与失活Fra(X)表达的研究结果提示:女性杂合子的智力水平与含有活性脆性X细胞的比例有关。对脆性X综合征的主要临床症状进行分析表明某些症状如脸形异常、大耳、大睾丸、身体过重或过长,对提示诊断具有重要意义。

A screening for fragile X in 140 children with congenital mental retardation was carried out by using the method of TC 199+Fudr;10 patients with fragile X were found.122 of 140 patients were from special schools and the incidence of fra (X) syndrome in the special schools was 5.74%(7/122). four pedigrees in this group were studied. five members of the families were found to be fragile X positive patients and 4 members were female carriers. The replication pattern of the fragile X was detected in fragile-X heterozygotes. The results suggest that the mental status of female carriers may be associated with the proportion of an early-replication fragile X.The analyses of the main clinical features reveal that abnormal face, large ears, macroorchidism and overweight or overgrowth are of significant diagnostic value in the studies of fra(X)syndrome.