Department of Neurology, Princess Margaret Hospital for Children, Perth, WA, Australia.
School of Paediatrics and Child Health, University of Western Australia, Perth, WA, Australia.
Eur J Clin Nutr. 2019 Jun;73(6):961-965. doi: 10.1038/s41430-018-0286-8. Epub 2018 Aug 14.
Nonketotic hyperglycinemia (NKH) is a devastating inborn error of glycine metabolism caused by deficient activity of the glycine cleavage enzyme. Classically, patients present with lethargy, hypotonia, myoclonic jerks, transient respiratory depression in the first week of life and often progress to death. Surviving infants have profound psychomotor retardation, refractory epilepsy and poor quality of life. Currently, no effective therapeutic avenues exist for severe NKH. Ketogenic diet (KD) has been trialled only in a small group of patients with neonatal NKH and early myoclonic encephalopathy, in whom significant improvements in seizure control were reported. We describe an infant with classical neonatal NKH who presented on the third day of life with hypotonia, poor feeding, respiratory insufficiency resulting in ventilatory support and seizures with burst-suppression pattern on electroencephalogram (EEG). KD initiated at age 6 months for intractable seizures, lead to a dramatic decrease in seizure frequency, EEG improvements, normalisation of plasma glycine levels, reduced spasticity and improved quality of life. KD may be a valuable treatment modality for refractory seizure control in classical NKH.
非酮症高甘氨酸血症（NKH）是一种由甘氨酸裂解酶活性缺乏引起的严重遗传性甘氨酸代谢障碍。典型表现为患儿在生后第一周出现嗜睡、肌张力低下、肌阵挛、一过性呼吸抑制，常进展为死亡。存活的患儿存在严重的精神运动发育迟缓、难治性癫痫和生活质量差。目前，NKH 尚无有效的治疗方法。生酮饮食（KD）仅在少数新生儿 NKH 和早发性肌阵挛性脑病患者中进行了试验，这些患者报告称在控制癫痫发作方面有显著改善。我们描述了一例具有典型新生儿 NKH 的患儿，其在生后第 3 天出现肌张力低下、喂养不良、呼吸功能不全导致需要通气支持和脑电图上出现爆发抑制模式的癫痫发作。该患儿在 6 月龄时因难治性癫痫发作开始 KD 治疗，结果导致癫痫发作频率显著降低、脑电图改善、血浆甘氨酸水平正常化、痉挛减少和生活质量提高。KD 可能是治疗经典 NKH 难治性癫痫发作的有效方法。
