TSFM is a nuclear gene encoding the elongation factor Ts (EFTs), an essential component of mitochondrial translational machinery. Impaired mitochondrial translation is responsible for neurodegenerative disorders characterized by multiple respiratory chain complex defects, multisystemic involvement, and neuroradiological features of Leigh-like syndrome. With the use of a next-generation sequencing (NGS)–based multigene panel for mitochondrial disorders, we identified the novel TSFM homozygous variant c.547G>A (p.Gly183Ser) in a 5-year-old boy with infantile early onset encephalocardiomyopathy, sensorineural hearing loss, and peculiar partially reversible neuroimaging features. Our findings expand the phenotypic spectrum of TSFM-related encephalopathy, offering new insights into the natural history of brain involvement and suggesting that TSFM should be investigated in pediatric mitochondrial disorders with distinctive neurologic and cardiac involvement.

中文翻译：

---

与脑心肌病相关的新型纯合TSFM致病变异，伴有感音神经性听力损失和特殊的神经放射学发现。

TSFM是一个编码延伸因子Ts（EFTs）的核基因，Ts是线粒体翻译机制的重要组成部分。线粒体翻译受损是神经退行性疾病的原因，神经退行性疾病的特征是多个呼吸链复合体缺陷，多系统受累以及李氏综合征的神经放射学特征。通过使用基于下一代测序（NGS）的多基因线粒体线粒体疾病，我们在一名5岁男孩患有婴儿早期发作性脑心肌病的男孩中鉴定了新型TSFM纯合变异体c.547G> A（p.Gly183Ser） ，感觉神经性听力丧失和特殊的部分可逆的神经影像学特征。我们的发现扩大了TSFM的表型谱相关的脑病，为脑部受累的自然史提供了新的见识，并建议应针对具有独特的神经系统和心脏受累的儿童线粒体疾病研究TSFM。