X染色体脆性综合征[fra(X)]是智力低下的常见原因,为X连锁遗传。因25%的携带者智力正常,所以携带者的诊断很困难,需要一个好的邻近多态DNA位点结构图来帮助进行携带者的检出。本文使用标准法进行了DNA标记的Southern印迹分析。用4种侧翼探针(Fg、St14、52A、DX13)对147个fra(X)综合征的系谱进行了 X-chromosome friability syndrome [fra (X)] is a common cause of mental retardation and is X-linked. Because 25% of carriers have normal intelligence, carrier diagnosis is difficult and requires a good, near-polymorphic DNA site map to aid carrier detection. Southern blot analysis of DNA labeling was performed using standard methods. The pedigree of 147 fra (X) syndromes was subjected to four flanking probes (Fg, St14, 52A, DX13)