一种新的NADH-细胞色素b5还原酶基因点突变

A novel point mutation in NADH cytochrome b5 reductase gene

目的 为了查明中国人遗传性高铁血红蛋白血症（ＲＣＭ） 患者的ＮＡＤＨ细胞色素ｂ５ 还原酶（ｂ５Ｒ） 基因突变类型，探讨ＲＣＭ 发生的分子机制。方法 从已报道的１ 例ＲＣＭⅠ型患者的外周血白细胞中提取ＲＮＡ，应用逆转录聚合酶链反应法（ＲＴＰＣＲ） 扩增了ｂ５ＲｃＤＮＡ（９２１ ｂｐ），测定其ｂ５ＲｃＤＮＡ的全部编码序列。结果 ｂ５ＲｃＤＮＡ基因的第２０３ 位密码子存在（ＴＧＣ→ＴＡＣ）Ｃｙｓ→Ｔｙｒ 的错义突变。经基因组ＰＣＲ限制性片段长度多态性（ＲＦＬＰ） 分析证实该突变并非ＰＣＲ过程中的错配。结论 Ｃｙｓ２０３ →Ｔｙｒ 是ＲＣＭ

Objective To characterize the b5R gene mutation in a Chinese patient with recessive congenital methemoglobinemia type Ⅰ(RCM Ⅰ).Methods Total RNA was extracted from the peripheral leukocytes of the patient and cDNA was synthesized by RT PCR. The coding region of b5R cDNA (921?bp) was analysed by sequencing of the RT PCR products.Results and Conclusion A novel mutation of Cys203(TGC)→Try(TAC) in exon 7 was identified,which was further confirmed by restriction enzyme analysis of the genomic DNA fragment.