用dystrophin　cDNA1－7的三个亚探针检出四个新的TaqⅠ限制性片段长度多态

Four new Taq Ⅰ polymorphisms detected by three subprobes from the dystrophin cDNA1-7

报道在ｄｙｓｔｒｏｐｈｉｎ基因内新发现四个ＴａｑⅠ限制性片段长度多态，用ｄｙｓｔｒｏｐｈｉｎｃＤＮＡ１—２ａ检测到的ＴａｑⅠ等位片段是４．０ｋｂ（Ａ１）和３．３ｋｂ（Ａ２），用ＣＤＮＡ２ｂ—３检测到的ＴａｑⅠ等位片段是７．２ｋｂ（Ａ１）和６．８ｋｂ（Ａ２）。用ｃＤＮＡ５ｂ—７检测到两对新的ＴａｑⅠ等位片段，分别是１０．０ｋｂ（Ａ１）和８．４ｋｂ（Ａ２），以及２．５５ｋｂ（Ｃ１）和１．６ｋｂ（Ｃ２）片段。在４５个ＤＭＤ／ＢＭＤ家系的基因检测中，这四对新的等位片段，在部分家系的上下代传递中分别呈孟德尔遗传学分离。它们的实际观察杂合体频率依次是：０．２９，０．０７，０．０４和０．１８，预期杂合体频率是０．２０，０．０６，０．０２和０．２０。这些新的ＴａｑⅠ限制性片段长度多态，已在杜氏肌营养不良症家系的遗传连锁分析及致病基因携带者的诊断中，显示出较高的；临床应用价值。

Four new Taq Ⅰ polymorphisms in dystrophin gene are reported here. A pair of allele fragment (4. 0 kb and 3. 3 kb) were detected by cDNA1- 2a,another pair (7. 2 kb and 6. 8 kb) by cDNA 2b - 3,and the other two pairs (10. 0kb and 8. 4kb, 2. 55kb and 1. 6kb) by cDNA 5b-7. The observed heterozygote frequencies (OHF) of the Four RFLPs were 0. 29,0. 07,0. 04 and 0. 18 respectively and the expected heterozygote frequencies (EHF) of them were 0. 20,0. 06,0. 02 and 0. 20. They had been tested in linkage analysis of DMD families and had shown a high utility in clinics.