Leigh syndrome is a clinically and radiologically heterogeneous condition with approximately 75 genes, nuclear and mitochondrial, known to be implicated in its pathogenesis. Leigh syndrome due to complex II deficiency constitutes 2% to 7% of these cases. Previously, nine individuals with Leigh syndrome have been reported with pathogenic variants in SDHB, which encodes for the iron–sulfur cluster subunit of mitochondrial respiratory chain complex II. The proband presented with Leigh syndrome. Exome sequencing revealed a homozygous missense variant p.(Ala102Thr) in SDHB. In silico protein modeling of the wild‐type and mutant proteins showed potentially decreased protein stability. We hereby report another individual with Leigh syndrome due to SDHB‐related mitochondrial complex II deficiency and review the phenotype and genotype associated with this condition.

中文翻译：

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SDHB中的新型变异p.（Ala102Thr）导致线粒体复合物II缺陷：病例报告和文献复习

Leigh 综合征是一种临床和放射学异质性疾病，大约有 75 个基因，核和线粒体，已知与其发病机制有关。由复杂 II 缺陷引起的 Leigh 综合征占这些病例的 2% 至 7%。此前，已有 9 名 Leigh 综合征患者被报道在 SDHB 中存在致病变异，该变异编码线粒体呼吸链复合体 II 的铁硫簇亚基。先证者出现 Leigh 综合征。外显子组测序揭示了 SDHB 中的纯合错义变异 p.(Ala102Thr)。野生型和突变型蛋白质的计算机蛋白质建模显示可能降低蛋白质稳定性。