Recurrent deletion in glycine decarboxylase gene and nonketotic hyperglycinemia Medical genetics, Research

甘氨酸脱羧酶基因反复缺失与非酮症高甘氨酸血症医学遗传学、研究

• 批准号: 10672134
• 负责人: KURE Shigeo
• 金额: $ 1.98万
• 依托单位: TOHOKU UNIVERSITY
• 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-10672134/
• 关键词: glycine decarboxylase; Alu repeats; non-ketotic hyperglycinemia; deletion; homologous recombination; glycine decarboxylase; Nonketotic hyperglycinemia; Homologous recombination; ghycime decarboxylase; nonkefotic hyperglycimemia; homologous recom

Mutations in glycine decarboxylase gene (GLDC) cause nonketotic hyperglycinemia (NKH), an inborn error of metabolism characterized by severe neurological disturbance. We determined the structures of GLDC and its pseudogene (psiGLDC) and studied their expression in molecular analysis of NKH. The GLDC gene spanned a least 135 kb and consisted of 25 exons. All donor and acceptor sites adhered to the canonical GT-AG rule except for the donor site of intron 21, where a variant form GC was used instead of GT. The transcription initiation site was assigned to a residue 163 bp upstream from the translation initiation triplet by primer extension analysis. The psiGLDC gene had no intron and shared 97.5% homology with the coding region of functional GLDC, suggesting that psiGLDC ia a processed pseudogene that arose from the GLDC transcript about 4 to 8 million years ago. RNA blotting analysis revealed that GLDC is expressed in human liver, kidney, brain and placenta. We then examined a patient with NKH with no detectable GLDC mRNA in his lymphoblasts. Exons 1 to 3 of the functional GLDC gene from this patient were not amplified by PCR, whereas those from control subjects were amplified. These results suggest a large homozygous deletion (at least 30 kb) in the patient. We then devise a semi-quantitative PCR to estimate the number of GLDC alleles using psiGLDC as an internal control, and confirmed the homozygosity and heterozygosity of the deletion in the patient and his parents, respectively. Structural information of GLDC and psiGLDC should facilitate the molecular analysis of NKH.

甘氨酸脱羧酶基因（GLDC）中的突变引起非酮高血糖（NKH），这是一种以严重神经学障碍为特征的代谢的天生误差。我们确定了GLDC及其假基因（PSIGLDC）的结构，并研究了它们在NKH分子分析中的表达。 GLDC基因跨越了至少135 kb，由25个外显子组成。除了内含子21的供体站点外，所有供体和受体站点都符合规范的GT-AG规则，其中使用了变体形式GC代替GT。通过引物扩展分析，转录启动位点被分配给翻译起始三胞胎上游的残基163 bp。 PSIGLDC基因没有内含子，并与功能性GLDC的编码区共享97.5％的同源性，这表明psigldc ia大约4到800万年前从GLDC转录物中产生了一种已加工的假基因。 RNA印迹分析表明，GLDC在人肝，肾脏，脑和胎盘中表达。然后，我们检查了一名NKH患者，他的淋巴细胞中未检测到的GLDC mRNA。来自该患者的功能性GLDC基因的外显子1至3没有被PCR放大，而对照组受试者的外显子基因则被放大。这些结果表明患者中有大量的纯合缺失（至少30 kb）。然后，我们设计了一个半定量PCR，以使用PSIGLDC作为内部对照来估计GLDC等位基因的数量，并分别确认了患者及其父母中缺失的纯合性和杂合性。 GLDC和PSIGLDC的结构信息应促进NKH的分子分析。

项目成果

Kure S,et al.: "Prenatal diagnosis of nonketotic hyperglycinemia・・"Prenat. Diagn.. 19. 717-720 (1999)

Kure S 等人：“非酮症高甘氨酸血症的产前诊断……”Diagn.. 19. 717-720 (1999)

Kure S,et al.: "Tetrahydrobiopterin-responsive phenylalanine hydroxylase・・"J. Pediatr. 135. 375-378 (1999)

Kure S 等人：“四氢生物蝶呤响应性苯丙氨酸羟化酶……”J. Pediatr. 135. 375-378 (1999)

Kure S,at.al.: "A subtype of pyridoxime dependent epilepsy with・・・" J Inher Metabol Dis. 21. 431-432 (1998)

Kure S,at.al.：“吡哆肟依赖性癫痫亚型......”J Inher Metabol Dis. 21. 431-432 (1998)

Kure S.et al.: "Tetrahydrobiopterine-responsive phenylalanine hydrosylase deficiency"Journal of Pediatrics. 135. 357-378 (1999)

Kure S.等人：“四氢生物蝶呤反应性苯丙氨酸水解酶缺乏症”儿科杂志。

Fujii K, Matsubara Y, Akanuma J, Takahashi K, Kure S, Suzuki Y, Imaizumi M, Iinuma K, Sakatsme O, Rinaldo P, Kuniaki Narisawa.: "Mutation detection by TaqMan-allele specific amplification: its application to the molecular diagnosis of glycogen storage dis

Fujii K、Matsubara Y、Akanuma J、Takahashi K、Kure S、Suzuki Y、Imaizumi M、Iinuma K、Sakatsme O、Rinaldo P、Kuniaki Narisawa。：“TaqMan 等位基因特异性扩增的突变检测：其在分子诊断中的应用