ANALYSIS OF GENE ENCODING THE HUMAN N-METHYL-D-ASPARTATE RECEPTOR (NMDAR1) IN SCHIZOPHRENICS

作为初步研究，调查了正常日本人编码人类N-甲基-D-天冬氨酸受体(NMDAR1)的基因是否存在突变。研究对象为32名正常日本人志愿者，其中男18人，女14人。据报道，在正常的欧洲人和美国人中，编码人类NMDAR1的基因有两个部分发生突变(外显子21有12694个，外显子7有6254个)。在本研究中，我们分别用PCR-RFLP方法在正常日本人中检测了这两个已知突变的存在。结果，在这两个部分中都没有检测到突变。然而，在两部分中的一部分(外显子21中的12694)，限制性内切酶处理后最终产生的DNA条带的长度远远超出了我们已知的报道的预期。此外，在另一部分(外显子7中的6254)，限制性内切酶处理后的DNA条带长度与我们的预期相反，认为编码NMDAR1基因的突变在日本人中是不存在的，或者只以很低的频率存在。因此，NMDAR1基因的突变分析在精神分裂症的研究中似乎是不合适的。进一步推测，DNA条带长度的差异可能是由于日本人和西方人之间的种族差异造成的。

As a preliminary study, it was investigated in normal Japanese whether there was a mutation in the gene encoding the human N-methyl-D-aspartate receptor (NMDAR1) or not. Subjects were 32 normal volunteers of Japanese, who consisted of 18 males and 14 females. It has been alr eady reported that there are two portions showing a mutation in the gene encoding the human NMDAR1 in normal Eur opeans and Americans (12694 in exon 21 and 6254 in exon 7). In the present study, the existence of the already-known mutation in the two portions was separately examined with PCR-RFLP methods in the nor mal Japanese. As a result, no mutation was detected in either of the two portions. However, in one of the two portions (12694 in exon 21), the length of DNA band finally produced with restriction endonuclease treatment following PCR was long beyond our expectations from the already-known report. Futher, in another portion (6254 in exon 7), the length of DNA band after restriction endonuclease treatment was short against our expectations.It was consider ed that the mutation in the gene encoding NMDAR1 was absent in Japanese or existed only in a much low frequency. There fore, it seemed that the analysis of mutation in the gene encoding NMDAR1 was not appropriate in schizophr enia research. Further, the difference in the length of DNA band as the PCR-RFLP-induced products was presumed to be due to the racial difference between Japanese and Weaterners.