GENOME DIFFERENCE ANALYSIS BETWEEN MONOZYGOTIC TWINS DISCORDANT FOR NEUROPSYCHIATRIC DISORDERS

在1997年，我们得到了以下结果.我们将RLGS应用于颞叶癫痫、双相情感障碍和惊恐障碍不一致的单卵双胞胎的基因组。然而，我们发现没有可重复的RLGS点受影响和非受影响的双胞胎之间的差异。今年，我们发现了一个非常罕见的单卵双胞胎自闭症不一致的病例，并在知情同意的情况下采集了血液样本。我们试图克隆在去年的实验中发现的患有精神分裂症的受影响和未受影响的单卵双胞胎之间不同的RLGS斑点中包括的DNA片段（Tsujita等人，1998年）。在RLGS点间克隆人DNA片段时，我们遇到了原RLGS方法的困难。我们面临克隆问题的原因是，原始RLGS需要大量的人血，80 ml，并且在RLGS斑点中平均仅含有0.5 satto moles（5 × 10^<-19>）DNA，比通常用于PCR的DNA的量少1/10 ^5。Pst Ⅰ有5 ′和3 ′端突出，不便于PCR，因此，今年我们努力开发了一种改进的RLGS，它包括PCR过程，增加了RLGS斑点中所含的DNA量，减少了克隆所需的人血体积。我们已经基本完成了一个改进的RLGS的开发，并得到了几个RLGS模式。如果我们发现同卵双生子之间的不一致点与神经精神疾病不一致，这种新的改良RLGS将使克隆变得更加容易。由首席研究员开发的将基因组扫描与不一致的单卵双生子相结合的方法可能适用于具有复杂遗传基础的各种疾病的基因组机制的研究，以避免单卵双生子中的一个成员患上此类疾病，而不是单卵双生子中的一个成员患上此类疾病。双胞胎姐妹要避开的地方

In 1997, we obtained the following results.1. We applied RLGS to genomes from the monozygotic twins discordant for temporal lobe epilepsy, bipolar disorder and panic disorder. However, we found no reproducible RLGS spot difference between affected and non-affected twins. This year, we found a very rare case of monozygotic twin discordant for autism and collected blood samples with informed consents.2. We tried to cloning DNA fragments included in RLGS spots different between affected and non-affected monozygotic twins with schizophrenia that was found in the experiments last year (Tsujita et al., 1998). We faced with difficulties of the original RLGS method in the cloning of human DNA fragment among a RLGS spot. The reasons why we faced with the cloning problems were that the original RLGS required a large amount of human blood, 80ml, and contained only 0.5 satto moles(5*10^<-19>) DNA in average among a RLGS spot that was 1/10^5 less amount than that of DNA usually available for PCR.Moreover, the DNA fragments digested by the combination of NotI, PvuII, PstI had 5' and 3' overhanging ends that were inconvenient for PCR.Therefore, this year we made an effort to develop a modification of RLGS that included PCR process which increased an amount of DNA contained in a RLGS spot and decreased a required volume of human blood for thc cloning. We have almost completed to develop a modified RLGS and got a couple of RLGS patterns. This new modified RLGS must make the cloning easier if we find discordant spots between identical twins discordant for neuropsychiatric disorders.The method developed by principal investigator that combines genome scanning with discordant monozygotic twins may be available for various kind s of disorders with complex genetic basis in the investigation of genomic mechanisms to be avoided suffering from such disorders by one member of a monozygotic twin pair and not to be avoided by the co-twin.