Blanco-Barca M O, Gómez-Lado C, Campos-González Y, Castro-Gago M
Servicio de Neuropediatría, Departamento de Peditría, Hospital Clínico Universitario, Santiago de Compostela.
Neurologia. 2007 Apr;22(3):191-5.
Mitochondrial DNA depletion (mtDNA) is an highly heterogeneous condition characterized by a decreased number of mtDNA copies.
The patient is a 22-month-old girl with generalized hypotonia, marked weakness, respiratory failure, arterial hypertension, hyperlactacidemia, hepatosplenomegaly and mild hypertransaminasemia without hepatic failure neither hypoketotic hypoglycemia. Electromyographic findings were consistent with neuromyopathy and muscle biopsy suggested a neurogenic atrophy. Electron microscopy revealed lipid droplets, subsarcolemmal accumulation of mitochondrias and glycogen granules. Respiratory chain enzime activities were normal. Genetic study in muscle showed mtDNA depletion, and the diagnosis of spinal muscular atrophy caused by survival motoneuron gene deletion was excluded.
This case might be a novel phenotype of mtDNA depletion which could be named hepatomioneuropatyc form. A normal result of respiratory chain enzimes in muscle doesn't excluded mtDNA depletion.
线粒体DNA耗竭(mtDNA)是一种高度异质性疾病,其特征是mtDNA拷贝数减少。
该患者为一名22个月大的女童,有全身肌张力减退、明显肌无力、呼吸衰竭、动脉高血压、高乳酸血症、肝脾肿大和轻度转氨酶升高,无肝衰竭及低酮性低血糖。肌电图检查结果与神经肌肉病一致,肌肉活检提示神经源性萎缩。电子显微镜检查发现脂滴、线粒体肌膜下积聚和糖原颗粒。呼吸链酶活性正常。肌肉的基因研究显示mtDNA耗竭,排除了由存活运动神经元基因缺失引起的脊髓性肌萎缩症的诊断。
该病例可能是mtDNA耗竭的一种新表型,可命名为肝肌神经病变型。肌肉中呼吸链酶结果正常并不能排除mtDNA耗竭。