Biallelic pathogenic variants in the neuroblastoma amplified sequence (NBAS) gene were firstly (2015) identified as a cause of fever-triggered recurrent acute liver failure (RALF). Since then, some patients with NBAS deficiency presenting with neurologic features, including a motor delay, intellectual disability, muscular hypotonia and a mild brain atrophy, have been reported. Here, we describe a case of pediatric patient diagnosed with NBAS deficiency due to a homozygous c.2809C > G, p.(Pro937Ala) variant presenting with RALF with severe hyperammonemia, acquired microcephaly and progressive brain atrophy. Not reported in the literature findings include severe hyperammonemia during ALF episode, and neurologic features in the form of acquired progressive microcephaly with brain atrophy. The latter raises the hypothesis about a primary neurologic phenotype in NBAS deficiency.

神经母细胞瘤扩增序列中的双等位基因致病变异（NBAS) 基因首先（2015 年）被确定为发热引发的复发性急性肝功能衰竭（RALF）的原因。从那时起，一些 NBAS 缺乏症患者出现了神经系统特征，包括运动迟缓、智力障碍、肌张力减退和轻度脑萎缩，已有报道。在这里，我们描述了一例被诊断为 NBAS 缺乏症的儿科患者，原因是纯合子 c.2809C > G, p.(Pro937Ala) 变异表现为 RALF 并伴有严重的高氨血症、获得性小头畸形和进行性脑萎缩。文献中未报道的发现包括 ALF 发作期间的严重高氨血症，以及获得性进行性小头畸形伴脑萎缩形式的神经系统特征。后者提出了关于 NBAS 缺乏症的原发性神经表型的假设。