Abstract：
OBJECTIVE: Developmental and Epileptic Encephalopathies (DEEs) are rare neurological disorders characterized by early-onset medically resistant epileptic seizures, structural brain malformations, and severe developmental delays. These disorders can arise from mutations in genes involved in vital metabolic pathways, including those within the brain. Recent studies have implicated defects in the mitochondrial malate aspartate shuttle (MAS) as potential contributors to the clinical manifestation of infantile epileptic encephalopathy. Although rare, mutations in MDH1, MDH2, AGC1, or GOT2 genes have been reported in patients exhibiting neurological symptoms such as global developmental delay, epilepsy, and progressive microcephaly.
METHODS: In this study, we employed exome data analysis of a patient diagnosed with DEE, focusing on the screening of 1896 epilepsy-related genes listed in the HPO and ClinVar databases. Sanger sequencing was subsequently conducted to validate and assess the inheritance pattern of the identified variants within the family. The evolutionary conservation scores of the mutated residues were evaluated using the ConSurf Database. Furthermore, the impacts of the causative variations on protein stability were analyzed through I-Mutant and MuPro bioinformatic tools. Structural comparisons between wild-type and mutant proteins were performed using PyMOL, and the physicochemical effects of the mutations were assessed using Project Hope.
RESULTS: Exome data analysis unveiled the presence of novel compound heterozygous mutations in the GOT2 gene coding for mitochondrial glutamate aspartate transaminase. Sanger sequencing confirmed the paternal inheritance of the p.Asp257Asn mutation and the maternal inheritance of the p.Arg262Cys mutation. The affected individual exhibited plasma metabolic disturbances, including hyperhomocysteinemia, hyperlactatemia, and reduced levels of methionine and arginine. Detailed bioinformatic analysis indicated that the mutations were located within evolutionarily conserved domains of the enzyme, resulting in disruptions to protein stability and structure.
CONCLUSIONS: Herein, we describe a case with DEE82 (MIM: # 618721) with pathologic novel biallelic mutations in the GOT2 gene. Early genetic diagnosis of metabolic epilepsies is crucial for long-term neurodevelopmental improvements and seizure control as targeted treatments can be administered based on the affected metabolic pathways.
METHODS: In this study, we employed exome data analysis of a patient diagnosed with DEE, focusing on the screening of 1896 epilepsy-related genes listed in the HPO and ClinVar databases. Sanger sequencing was subsequently conducted to validate and assess the inheritance pattern of the identified variants within the family. The evolutionary conservation scores of the mutated residues were evaluated using the ConSurf Database. Furthermore, the impacts of the causative variations on protein stability were analyzed through I-Mutant and MuPro bioinformatic tools. Structural comparisons between wild-type and mutant proteins were performed using PyMOL, and the physicochemical effects of the mutations were assessed using Project Hope.
RESULTS: Exome data analysis unveiled the presence of novel compound heterozygous mutations in the GOT2 gene coding for mitochondrial glutamate aspartate transaminase. Sanger sequencing confirmed the paternal inheritance of the p.Asp257Asn mutation and the maternal inheritance of the p.Arg262Cys mutation. The affected individual exhibited plasma metabolic disturbances, including hyperhomocysteinemia, hyperlactatemia, and reduced levels of methionine and arginine. Detailed bioinformatic analysis indicated that the mutations were located within evolutionarily conserved domains of the enzyme, resulting in disruptions to protein stability and structure.
CONCLUSIONS: Herein, we describe a case with DEE82 (MIM: # 618721) with pathologic novel biallelic mutations in the GOT2 gene. Early genetic diagnosis of metabolic epilepsies is crucial for long-term neurodevelopmental improvements and seizure control as targeted treatments can be administered based on the affected metabolic pathways.
摘要：
目的：发育性和癫痫性脑病（DEEs）是罕见的神经系统疾病，其特征是早发性药物耐药性癫痫发作，脑结构性畸形,严重的发育迟缓.这些疾病可能是由涉及重要代谢途径的基因突变引起的。包括大脑中的那些。最近的研究表明，线粒体苹果酸天冬氨酸穿梭（MAS）的缺陷是婴儿癫痫性脑病临床表现的潜在贡献者。虽然罕见，MDH1，MDH2，AGC1或GOT2基因的突变已在表现出神经系统症状如整体发育迟缓的患者中报道，癫痫,进行性小头畸形.
方法：在本研究中，我们对一名诊断为DEE的患者进行了外显子组数据分析，重点筛选HPO和ClinVar数据库中列出的1896个癫痫相关基因。随后进行Sanger测序以验证和评估家族内鉴定的变体的遗传模式。使用ConSurf数据库评估突变残基的进化保守性得分。此外，通过I-Mutant和MuPro生物信息学工具分析了致病变异对蛋白质稳定性的影响。使用PyMOL进行野生型和突变蛋白之间的结构比较，使用希望工程评估突变的物理化学作用。
结果：外显子组数据分析揭示了编码线粒体谷氨酸天冬氨酸转氨酶的GOT2基因中存在新的复合杂合突变。Sanger测序证实了p.Asp257Asn突变的父系遗传和p.Arg262Cys突变的母系遗传。受影响的个体表现出血浆代谢紊乱，包括高同型半胱氨酸血症,高乳酸血症,蛋氨酸和精氨酸水平降低。详细的生物信息学分析表明，突变位于该酶的进化保守结构域内，导致蛋白质稳定性和结构的破坏。
结论：此处，我们描述了1例DEE82(MIM:#618721)在GOT2基因中出现病理新的双等位基因突变.代谢性癫痫的早期遗传诊断对于长期神经发育改善和癫痫发作控制至关重要，因为可以基于受影响的代谢途径进行靶向治疗。
方法：在本研究中，我们对一名诊断为DEE的患者进行了外显子组数据分析，重点筛选HPO和ClinVar数据库中列出的1896个癫痫相关基因。随后进行Sanger测序以验证和评估家族内鉴定的变体的遗传模式。使用ConSurf数据库评估突变残基的进化保守性得分。此外，通过I-Mutant和MuPro生物信息学工具分析了致病变异对蛋白质稳定性的影响。使用PyMOL进行野生型和突变蛋白之间的结构比较，使用希望工程评估突变的物理化学作用。
结果：外显子组数据分析揭示了编码线粒体谷氨酸天冬氨酸转氨酶的GOT2基因中存在新的复合杂合突变。Sanger测序证实了p.Asp257Asn突变的父系遗传和p.Arg262Cys突变的母系遗传。受影响的个体表现出血浆代谢紊乱，包括高同型半胱氨酸血症,高乳酸血症,蛋氨酸和精氨酸水平降低。详细的生物信息学分析表明，突变位于该酶的进化保守结构域内，导致蛋白质稳定性和结构的破坏。
结论：此处，我们描述了1例DEE82(MIM:#618721)在GOT2基因中出现病理新的双等位基因突变.代谢性癫痫的早期遗传诊断对于长期神经发育改善和癫痫发作控制至关重要，因为可以基于受影响的代谢途径进行靶向治疗。
