Gérard B, Le Heuzey M F, Brunie G, Lewine P, Saiag M C, Cacheux V, Da Silva F, Dugas M, Mouren-Simeoni M C, Elion J, Grandchamp B
Laboratoire de Biochimie Génétique, Hôpital Robert Debré, Paris, France.
Ann Genet. 1997;40(3):139-44.
In this study, we evaluated the prevalence of the fragile X syndrome in a cohort of 574 mentally retarded children. The only inclusion criterion was the diagnosis of mental retardation according to the DSM-IIIR classification. We used a PCR-based strategy for the diagnosis of fragile X syndrome to facilitate systematic screening. This diagnostic scheme is based on an initial PCR to eliminate most fragile X-negative patients followed by Southern blotting for fragile X syndrome diagnosis. Altogether, 403 boys and 171 girls were tested. The prevalence of this genetic disorder was 1.9% (11/574) in the whole cohort and 2.5% (10/403) in boys. Only one case of fragile X syndrome was detected among the 171 girls tested (0.6%). Clinical examination, especially in the youngest children, was often unremarkable, and the only reason for suspecting fragile X syndrome was the presence of mental retardation. Thus, a systematic screening for the fragile X syndrome in mentally retarded children seems justified because of the importance of a precise diagnosis in genetic counseling.
在本研究中，我们评估了574名智力发育迟缓儿童队列中脆性X综合征的患病率。唯一的纳入标准是根据《精神疾病诊断与统计手册第三版修订本》（DSM-IIIR）分类法诊断为智力发育迟缓。我们采用基于聚合酶链反应（PCR）的策略来诊断脆性X综合征，以利于进行系统筛查。该诊断方案基于最初的PCR以排除大多数脆性X阴性患者，随后进行Southern印迹法以诊断脆性X综合征。总共对403名男孩和171名女孩进行了检测。这种遗传性疾病在整个队列中的患病率为1.9%（11/574），在男孩中为2.5%（10/403）。在接受检测的171名女孩中仅检测到1例脆性X综合征（0.6%）。临床检查，尤其是对最小的儿童，通常无明显异常，怀疑脆性X综合征的唯一原因是存在智力发育迟缓。因此，鉴于精确诊断在遗传咨询中的重要性，对智力发育迟缓儿童进行脆性X综合征的系统筛查似乎是合理的。
