Martínez F, Badía L, Prieto F
Unidad de Genética y Diagnóstico Prenatal, Hospital Universitario La Fe, Valencia, Spain.
Clin Genet. 1992 Jul;42(1):22-6. doi: 10.1111/j.1399-0004.1992.tb03130.x.
A fragile X family is described which shows two interesting features. In a sibship of seven, the two males and four of the five females are affected with mental retardation. Since the only normal daughter is not a carrier, the penetrance of the fragile X mutation in carrier daughters is 100%. Nevertheless, the penetrance of this syndrome in affected daughters of normal mothers has been estimated at a third. Also, DNA typing analysis of flanking RFLP markers revealed a higher than expected number of crossing-overs. We also include the molecular study of the mutation in the (CGG)n repeat of the FMR-1 gene.
描述了一个脆性X家族，该家族呈现出两个有趣的特征。在一个有七个孩子的家庭中，两个男性和五个女性中的四个患有智力迟钝。由于唯一正常的女儿不是携带者，携带者女儿中脆性X突变的外显率为100%。然而，正常母亲的患病女儿中该综合征的外显率估计为三分之一。此外，侧翼RFLP标记的DNA分型分析显示交叉的数量高于预期。我们还包括了对FMR-1基因（CGG）n重复序列中突变的分子研究。
