Analysis of point mutations in the ryanodine receptor gene from malignant hyperthermia patients who showed highly accelerated CICR

恶性高热加速CICR患者兰尼碱受体基因点突变分析

• 批准号: 10671405
• 负责人: HAGRWARA Keiko Oguchi
• 金额: $ 2.37万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10671405/
• 关键词: Malignant Hyperthermia; CICR; RYR1; point mutations; リアノジン受容体遺伝子(RYR1); リアノジン受容体遺伝子(RYRI)

Malignant hyperthemia (MH) is a potentially fatal complication of general anesthesia resulting from abnormal CaィイD12+ィエD1-induced CaィイD12+ィエD1 release (CICR) via the type 1 ryanodine receptor (RYR1) in skeletal muscle. Dr. Kawana et al. (Department of Pharmacology, Graduate School of Medicine, The University of Tokyo) had analyzed CICR in biopsied skeletal muscle samples obtained from 84 patients who underwent surgery, and identified three patients with highly accelerated CICR rates and a clear history of MH incidence. MIH often has a familial background, and the presence of mutation in the RYR1 gene has been suspected. We analyzed genomic DNA prepared from the blood samples donated by these patients for determination of the entire 106 exons of the RYR1 gene. We found three point mutations (R4645Q. P4668S, L4838V) with alterations in the coded amino acid within the C-terminal region of the RYR1 gene. We did functional assay in CHO cells by expressing rabbit RYR1 channels carrying these mutations. Rabbit RYR1 channels carrying R4645Q and L4838V showed enhanced sensitivity to caffein. Furthermore, all three MH patients had one of the functionally significant mutations in the RYR1 gene. We conclude that these point mutations cause malignant hyperthermia to 3 patients with highly accerelated CICR.

恶性高热症（malignant hyperthemia，MH）是全身麻醉后一种潜在的致死性并发症，由骨骼肌1型兰尼碱受体（Ryanodine receptor，RYR 1）介导的异常Ca ~（2+）D12+ Ca ~（2+）D1释放（Ca ~（2+）D12+ Ca ~（2+）D1 release，CICR）引起。Dr. Kawana等人（东京大学医学研究生院药理学系）分析了从84例接受手术的患者中获得的活检骨骼肌样本中的CICR，并确定了3例具有高度加速的CICR率和明确的MH发病史的患者。MIH通常具有家族背景，并且RYR 1基因突变的存在一直被怀疑。我们分析了从这些患者捐献的血液样本中制备的基因组DNA，以确定RYR 1基因的全部106个外显子。我们发现了三个点突变（R4645 Q。P4668 S，L4838 V），在RYR 1基因的C-末端区域内的编码氨基酸中具有改变。我们通过表达携带这些突变的兔RYR 1通道在CHO细胞中进行了功能测定。携带R4645 Q和L4838 V的兔RYR 1通道对咖啡因的敏感性增强。此外，所有三名MH患者在RYR 1基因中都有一个功能显著的突变。我们的结论是，这些点突变导致恶性高热3例高度accerrelated CICR。