Clinical and molecular studies on in born errors of ketone body metabolism

酮体代谢先天性缺陷的临床和分子研究

• 批准号: 14570735
• 负责人: FUKAO Toshiyuki
• 金额: $ 2.56万
• 依托单位: GIFU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570735/
• 关键词: Thiolase deficiency; ketone body; inborn errors of metabolism; CoA transferase; ketoacidosis; mutation; β-ケトチオラーゼ欠損症; サクシニル-CoA:3-ケト酸CoAトランスフェラーゼ欠損症; 変異; 有機酸; 極長鎖アシル-CoA脱水素酵素欠損症; 遺伝子解析; ノックアウトマウス; ミトコンドリア

SCOT deficient patients with "mild" mutation : We analyzed 3 Japanese families with SCOT deficient patients at the clinical and molecular level. We disclosed that SCOT deficient patients with "mild" mutations do not show a pathognomonic permanent ketosis. This indicates that we can not exclude SCOT deficiency if patients do not have permanent ketosis (Submitted).Characterization of mutations at the initiator methionine codon in T2 deficiency : We identified an initiator codon mutation, c.2T>C, heterozygously in GK30 (The other mutation was 149delC). We made expression vectors for 9 possible missense mutations at the initiator codon and analyzed the efficiency of translation initiation at the mutant initiator codons. Although the efficiencies were variable among the mutations, all the mutant initiator methionine codons were functioned as the initiator codon. Hence we concluded that initiator codon mutations result in "mild" mutations in T2 deficiency (2003).Characterization of T2 defici … More ent patients with "mild" mutations : We analyzedphenotype/genotype correlation in 5 Japanese T2 deficient patients and revealed characters for T2 deficient patients with "mild" mutations. We found no significant differences in the frequency and severity of ketoacidotic crises between patients "mild" and "severe" mutations. However, during non-episodic condition, abnormalities in urinary organic acid and blood acylcarnitine profiles was subtle in patients with "mild" mutations and they, can be missed as normal if these analyses are performed during non-episodic condition (2003). We also raised a possibility that patients with "mild" mutations were mis-diagnosed as normal by a coupled assay with tyglyl-CoA (submitted)SCOT, 3HBD knockout mice : We cloned genomic fragments necessary for construction of knockout constracts and are still making constructs.Establishment of enzyme assay for 2-methyl-3-hydroxybutyrate dehydrogenase deficiency and its clinical analysis : We established enzyme assay method for this enzyme using fibroblasts and lymphocytes. We did not find this enzyme defect in cell lines which were previously ruled out T2 deficiency. Less

“轻度”突变的SCOT缺陷患者：我们从临床和分子水平分析了3个日本SCOT缺陷患者家庭。我们发现，具有“轻度”突变的SCOT缺陷患者不表现出典型的永久性酮症。这表明如果患者没有永久性酮症，我们不能排除SCOT缺乏症（提交）。T2缺乏症启动子蛋氨酸密码子突变的特征：我们在GK30中发现了一个启动子突变C . 2t >C（另一个突变是149delC）。我们制作了9个启动密码子可能错义突变的表达载体，并分析了突变启动密码子的翻译起始效率。虽然不同突变体的效率不同，但所有突变体的启动蛋氨酸密码子都具有启动密码子的功能。因此，我们得出结论，启动密码子突变导致T2缺乏症的“轻度”突变（2003）。T2缺陷的特征和更多的“轻度”突变患者：我们分析了5例日本T2缺陷患者的表型/基因型相关性，揭示了T2缺陷“轻度”突变患者的特征。我们发现“轻度”和“重度”突变患者发生酮症酸中毒的频率和严重程度没有显著差异。然而，在非发作性疾病中，“轻度”突变患者的尿有机酸和血液酰基肉碱谱异常是微妙的，如果在非发作性疾病中进行这些分析，它们可能会被遗漏（2003）。通过与tyglyl-CoA（提交的）SCOT、3HBD敲除小鼠的偶联试验，我们也提出了“轻度”突变患者被误诊为正常的可能性：我们克隆了构建敲除结构所需的基因组片段，目前仍在构建结构。2-甲基-3-羟基丁酸脱氢酶缺乏症酶检测方法的建立及临床分析：以成纤维细胞和淋巴细胞为检测对象，建立了2-甲基-3-羟基丁酸脱氢酶的酶检测方法。我们没有在细胞系中发现这种酶缺陷，之前已经排除了T2缺乏。少

项目成果

Takusa Y: "Identification and characterization of temperature-sensitive mild mutations in 4 VLCAD deficient patients with non-severe childhood form"Mol Genet Metab. 75. 227-234 (2002)

Takusa Y：“4 名非严重儿童期 VLCAD 缺陷患者的温度敏感性轻度突变的鉴定和表征”Mol Genet Metab。

Beamish H: "Functional link between BLM defective in Bloom's syndrome and the ataxia-telangiectasia mutated protein, ATM"J Biol Chem. 277. 30615-30525 (2002)

Beamish H：“布卢姆综合征中 BLM 缺陷与共济失调毛细血管扩张突变蛋白 ATM 之间的功能联系”J Biol Chem。

Fukao T: "Single base substitutions at the initiator codon in the mitochondrial acetoacetyl-CoA thiolase (ACAT1/T2) gene result in production of varying amounts of wild-type T2 polypeptide"Hum Mutat. (in press).

Fukao T：“线粒体乙酰乙酰辅酶A硫解酶（ACAT1/T2）基因中起始密码子的单碱基取代导致产生不同数量的野生型T2多肽”Hum Mutat。

Kasahara Y, et al.: "Hyper-IgM syndrome with putative dominant negative mutation in activation-induced cytidine deaminase."J Allergy Clin.Immunol. 112. 762-767 (2003)

Kasahara Y 等人：“在激活诱导的胞苷脱氨酶中推定显性失活突变的高 IgM 综合征。”J Allergy Clin.Immunol。

Fukao T, et al.: "Disruption of the BLM gene in ATM-null DT40 cells does not exacerbate either phenotype."Oncogene. (in press).

Fukao T 等人：“ATM 无效 DT40 细胞中 BLM 基因的破坏不会加剧任何一种表型。”癌基因。