Filippi G, Rinaldi A, Archidiacono N, Rocchi M, Balazs I, Siniscalco M
Am J Med Genet. 1983 May;15(1):113-9. doi: 10.1002/ajmg.1320150115.
Eighteen Sardinian pedigrees segregating for the X-fragile site syndrome were studied with respect to the segregation of the fragile site (FS) at Xq28, mental retardation, and macro-orchidism. No exception was found in the association of this symptomatic triad (MOM-X) in 41 out of 42 patients examined. The exceptional individual had micro- rather than macro-orchidism and was found to have a 47, XXY sex chromosome complement. In six informative sibships, the MOM-X syndrome was found to segregate in close linkage association with G6PD-deficiency or protan colorblindness. The maximum likelihood estimate of recombination if 6% with 90% fiducial limits between 2.5 and 19.5% and an odds ratio in favor of measurable linkage of 428:1. However, no hint of measurable linkage was found in six pedigrees segregating for G6PD and the Renpenning syndrome or other unspecified types of X-linked mental retardation. These data give strong support to the generally held hypothesis that the FS at Zq28, characteristic of the MOM-X syndrome, is a direct expression of a genetic change in the same chromosomal region. They also clearly suggest that X-linked MR without FS may be the result of different allelic mutations at the same locus.
对18个患有X脆性位点综合征的撒丁岛家系进行了研究，涉及Xq28处脆性位点（FS）的分离、智力迟钝和巨睾症。在42名接受检查的患者中，有41名患者的这种症状三联征（MOM-X）关联情况无异常。例外的个体患有微睾症而非巨睾症，且发现其性染色体组成为47, XXY。在6个提供信息的同胞关系中，发现MOM-X综合征与G6PD缺乏症或红色盲紧密连锁。重组的最大似然估计值为6%，90%的置信区间为2.5%至19.5%，支持可测量连锁的优势比为428:1。然而，在6个分离G6PD和伦彭宁综合征或其他未指定类型X连锁智力迟钝的家系中，未发现可测量连锁的迹象。这些数据有力地支持了普遍持有的假设，即MOM-X综合征特有的Xq28处的FS是同一染色体区域遗传变化的直接表现。它们还清楚地表明，没有FS的X连锁智力迟钝可能是同一基因座不同等位基因突变的结果。
