Gayol L, Ferreiras R, Alvarez J
Instituto de Neurología y Neurocirugía, La Habana, Cuba.
Arch Neurobiol (Madr). 1991 Mar-Apr;54(2):41-7.
A family study and detection of bearer individuals has been carried out in five families suffering from the fragile X syndrome by means of clinical and cytogenetical examination, as well as by DNA recombination techniques in one of them. In 14 males the X marker chromosome was found. In 45 females studied in order to find bearer features, 23 heterozygote individuals have been detected. Out of those 23 cases, 11 were fragile X positive and in the remaining 22 a previous risk of 25-50% was estimated. In this group we used the Bayes theorem considering as conditional probabilities to bear a healthy male and to be fragile negative and the risk of being a bearer person decreased in all the cases. The significance and difficulties of the genetical prevention in families suffering from this syndrome because of the great number of young female with risk at the reproductive age are debated. The DNA study with the St14 sound (DXS52 Locus) in a family was concordant with the cytogenetical studies. A possible recombination in an individual suffering from fixation, atypical phenotype and low percentage of the maker expression.
通过临床和细胞遗传学检查，以及其中一个家庭采用DNA重组技术，对五个患有脆性X综合征的家庭进行了家系研究和携带者个体检测。在14名男性中发现了X标记染色体。为了寻找携带者特征对45名女性进行了研究，检测出23名杂合子个体。在这23例中，11例脆性X阳性，其余22例先前估计有25%-50%的风险。在该组中，我们使用贝叶斯定理，将生育健康男性和脆性X阴性视为条件概率，在所有病例中携带者风险均降低。由于育龄期有风险的年轻女性数量众多，讨论了该综合征家庭遗传预防的意义和困难。在一个家庭中用St14探针（DXS52位点）进行的DNA研究与细胞遗传学研究结果一致。在一个患有固定化、非典型表型和标记表达率低的个体中可能发生了重组。
