Young R S, Jaramillo C, McCombs J L, Moore C M, Jorgenson R J
South Med J. 1986 Apr;79(4):405-9. doi: 10.1097/00007611-198604000-00004.
The fragile-X mental retardation syndrome is the second most common identifiable cause of mental retardation in man. This condition violates many of the expectations for X-linked disorders, including the transmission of the syndrome through men who carry the gene but, for unknown reasons, do not express it. Two new cases of male transmission are presented along with four other cases heretofore unidentified in the literature, bringing the total number of confirmed or probable cases of transmission through normal men to 32. The various unorthodox characteristics of the syndrome are reviewed in light of their influence on genetic counseling. Recommendations for counseling families with fragile-X include evaluating all sons of carrier women psychometrically and cytogenetically, abandoning termination of pregnancies with male fetuses as a means of preventing the fragile-X syndrome, assuming that all mothers of sporadic cases are carriers, and karyotyping at-risk female members at an early age.
脆性X智力低下综合征是人类第二常见的可识别智力低下病因。这种病症违背了许多对X连锁疾病的预期，包括该综合征通过携带基因但因不明原因未表达的男性进行传递。本文报告了两例男性传递的新病例以及文献中迄今未识别的其他四例病例，使经正常男性传递的确诊或疑似病例总数达到32例。鉴于其对遗传咨询的影响，对该综合征的各种非传统特征进行了综述。为脆性X综合征家庭提供咨询的建议包括对携带者女性的所有儿子进行心理测量和细胞遗传学评估，放弃将男性胎儿终止妊娠作为预防脆性X综合征的手段，假定所有散发病例的母亲均为携带者，并在幼年对有风险的女性成员进行核型分析。
