Department of Medical Genetics, Ege University Faculty of Medicine, Izmir, Turkey.
Department of Medical Genetics, Ege University Faculty of Medicine, Izmir, Turkey.
Clin Neurol Neurosurg. 2022 Jan;212:107039. doi: 10.1016/j.clineuro.2021.107039. Epub 2021 Nov 20.
Isolated deficiency of complex II is a rare inborn error of metabolism, accounting for approximately 2% of mitochondrial diseases. Mitochondrial complex II deficiency is predominantly seen in cases with bi-allelic SDHA mutations. To our knowledge, only 11 patients and five pathogenic variants have been reported for the SDHB gene. Our patient had a severe clinical presentation with seizures and sepsis, and died at the age of 2 months. Muscle biopsy analysis was compatible with mitochondrial myopathy with complex II deficiency. The family was given a molecular diagnosis for their child 2 years after his death via a clinical exome test of a frozen muscle biopsy specimen and a novel homozygous missense variant c.592 A>G (p.Ser198Gly) in SDHB gene was detected by next-generation sequencing. Here, we present another patient with a novel homozygous SDHB variant causing severe complex II deficiency and early death.
SDHB 基因致单纯型 II 复合体缺陷病 1 例报告
单纯型 II 复合体缺陷病是一种罕见的遗传性代谢缺陷病，约占线粒体疾病的 2%。线粒体复合体 II 缺陷主要见于双等位基因 SDHA 突变病例。据我们所知，目前仅报道了 11 例患者和 5 种致病性变异体。我们的患者临床表现严重，有癫痫发作和脓毒症，2 个月大时死亡。肌肉活检分析与伴有 II 复合体缺陷的线粒体肌病一致。在患儿死亡 2 年后，通过对冷冻肌肉活检标本进行临床外显子组测试和下一代测序检测到 SDHB 基因的新型纯合错义变异 c.592A>G(p.Ser198Gly)，该家系获得了分子诊断。本文报道了另 1 例由新型纯合 SDHB 变异导致的严重 II 复合体缺陷病和早期死亡的患者。
