Mongini T, Doriguzzi C, Chiadò-Piat L, Silvestri G, Servidei S, Palmucci L
Paolo Peirolo Centre for Neuromuscular Diseases, Department of Neurosciences, University of Turin, Italy.
Clin Neuropathol. 2002 Mar-Apr;21(2):72-6.
Four members of a family were found to carry the A3243G mtDNA mutation. Clinical features varied from typical MELAS to myoclonic epilepsy to simple deafness without neurological signs. Several other members of the family had symptoms consistent with a mitochondrial disease. Muscle biopsy in 3 of the 4 patients showed the most prominent mitochondrial alterations with partial deficiency of cytochrome c oxidase in the case with the mildest phenotype. Mitochondrial DNA analysis detected a variable percentage of A3243G mutation, roughly correlating with the phenotype. The interesting feature of the family lies in the great intrafamilial variability of the severity of clinical expression, encompassing MELAS and MERRF features, associated with the A3243G mtDNA mutation. A search for the most common mtDNA mutations is recommended in all patients featuring incomplete MELAS or MERRF syndromes and in all familial cases presenting minimal clinical signs.
一个家族的四名成员被发现携带A3243G线粒体DNA（mtDNA）突变。临床特征从典型的线粒体脑肌病伴乳酸血症和卒中样发作（MELAS）到肌阵挛性癫痫，再到无神经体征的单纯耳聋不等。该家族的其他几名成员也有与线粒体疾病相符的症状。4名患者中的3名进行了肌肉活检，在表型最轻的病例中显示出最显著的线粒体改变，伴有细胞色素c氧化酶部分缺乏。线粒体DNA分析检测到A3243G突变的比例各不相同，大致与表型相关。该家族的有趣特征在于临床表型严重程度在家族内部存在很大差异，包括MELAS和肌阵挛性癫痫伴破碎红纤维（MERRF）特征，且与A3243G mtDNA突变相关。对于所有具有不完全MELAS或MERRF综合征特征的患者以及所有临床体征轻微的家族性病例，建议筛查最常见的mtDNA突变。
