NARS2 mutations are known to cause various clinical phenotypes such as nonsyndromic hearing loss, Leigh/Alpers syndrome, refractory epilepsy, developmental delay, intellectual disability and myopathy. We presented the first Turkish variant of NASR2 and added type 1 diabetes mellitus (DM), which was not previously described in the phenotype spectrum of this disease. A 4.5-month-old girl presented with hearing loss, hypotonia, refractory myoclonic epilepsy, severe developmental delay and large subdural hemorrhage. In the first year of the follow-up, type 1 DM developed. A homozygous missense mutation, [c.500 A>G, p.H167R] in the NARS2 gene was detected in the trio-based whole-exome sequencing (WES). In this disease, in addition to multi-organ involvement, type 1 DM may also develop, as in our case. Since it is a mitochondrial disease, the decision to treat with valproic acid should be reconsidered. The long diagnostic process can be shortened with WES.

中文翻译：

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NARS2 变体中的一个新实体：第一例报告的与该表型相关的 1 型糖尿病病例。

已知 NARS2 突变会导致各种临床表型，例如非综合征性听力损失、Leigh/Alpers 综合征、难治性癫痫、发育迟缓、智力障碍和肌病。我们介绍了 NASR2 的第一个土耳其变体并添加了 1 型糖尿病 (DM)，这在该疾病的表型谱中以前没有描述过。一名 4.5 个月大的女孩因听力丧失、肌张力减退、难治性肌阵挛性癫痫、严重发育迟缓和硬膜下大出血就诊。在随访的第一年，出现了 1 型 DM。在基于三重奏的全外显子组测序 (WES) 中检测到 NARS2 基因中的纯合错义突变 [c.500 A>G, p.H167R]。在这种疾病中，除了多器官受累外，1 型 DM 也可能发生，就像我们的病例一样。由于它是一种线粒体疾病，应重新考虑使用丙戊酸治疗的决定。WES 可以缩短漫长的诊断过程。