Rocha Helena, Sampaio Mafalda, Rocha Ruben, Fernandes Susana, Leão Miguel
Department of Neurology, Centro Hospitalar São João, Porto, Portugal; Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Portugal.
Pediatric Neurology Unit, Department of Paediatrics, Centro Hospitalar São João, Porto, Portugal.
Eur J Med Genet. 2016 Sep;59(9):478-82. doi: 10.1016/j.ejmg.2016.05.017. Epub 2016 May 31.
MEF2C haploinsufficiency syndrome is characterized by severe intellectual disability, epilepsy, stereotypic movements, minor dysmorphisms and brain abnormalities. We report the case of a patient with a new MEF2C mutation, comparing his clinical and imaging features to those previously reported in the literature.
A 10 year-old boy first came to pediatric neurology clinic at the age of 11 months because of severe psychomotor delay, without regression. He presented generalized hypotonia, poor eye contact, hand-mouth stereotypies, strabismus and minor facial dimorphisms. Epileptic seizures started at 26 months of age and were refractory. Brain MRI showed a slight increase in periventricular white matter signal and globally enlarged CSF spaces. Molecular analysis revealed a de novo, pathogenic and causative MEF2C mutation.
MEF2C haploinsufficiency syndrome was recently recognized as a neurodevelopmental disorder. Severe intellectual disability with inability to speak and epilepsy are universal features in patients with MEF2C mutations, although mild cognitive and speech disorders have been reported to occur in patients with duplications. Epilepsy might be absent in patients with partial deletions. Abnormal movement patterns are very common in patients with MEF2C haploinsufficiency. Delayed myelination seems to be more commonly observed in patients with MEF2C mutations, while malformations of cortical development were only reported in patients with microdeletions. Although MEF2C haploinsufficiency prevalence is yet to be determined, it should be considered in the differential diagnosis of patients with severe intellectual disability and Rett-like features.
MEF2C单倍剂量不足综合征的特征为严重智力残疾、癫痫、刻板运动、轻微畸形和脑部异常。我们报告了一例患有新的MEF2C突变的患者，将其临床和影像学特征与文献中先前报道的特征进行了比较。
一名10岁男孩在11个月大时因严重精神运动发育迟缓首次来到儿科神经科门诊，病情无倒退。他表现为全身肌张力低下、眼神交流差、手口刻板动作、斜视和轻微面部畸形。癫痫发作始于26个月大，且难以控制。脑部磁共振成像显示脑室周围白质信号略有增加，脑脊液间隙整体增大。分子分析显示存在一种新发的、致病性的、导致疾病的MEF2C突变。
MEF2C单倍剂量不足综合征最近被确认为一种神经发育障碍。MEF2C突变患者普遍存在严重智力残疾、无法说话和癫痫，尽管据报道重复患者会出现轻度认知和言语障碍。部分缺失患者可能无癫痫发作。异常运动模式在MEF2C单倍剂量不足患者中非常常见。MEF2C突变患者似乎更常观察到髓鞘形成延迟，而仅在微缺失患者中报告有皮质发育畸形。尽管MEF2C单倍剂量不足的患病率尚未确定，但在鉴别诊断严重智力残疾和具有雷特氏症样特征的患者时应予以考虑。
