阵发性运动诱发性运动障碍患者的临床表现及基因诊断

回顾性分析5例阵发性运动诱发性运动障碍(PKD)患儿的临床表现,并利用高通量测序及染色体微阵列技术分析患者的基因突变。5例患者中4例男性、1例女性,发病年龄为6~9岁。均因突然的运动、转身、惊吓或者精神紧张等因素诱发,表现为单侧或双侧的肢体姿势异常、手足徐动、面部肌肉抽搐以及身体姿势异常等,无意识障碍。发作频率从每月3~5次到每天2~7次,每次发作持续时间不超过30 s。脑电图均未见异常。3例患者均有类似发作的家族史。高通量测序发现4例患者存在PKD致病基因富脯氨酸跨膜蛋白2(PRRT2)突变,其中2例为c.649_650ins C(p.R217Pfs X8)杂合突变,1例为c.436CT(p.P146S)突变,1例为IVS2-1GA剪接位点突变,c.436CT与IVS2-1GA是未见报道的新发突变。对于基因检测阴性的1例患者行基因芯片检测,发现16号染色体p11.2区域缺失,大小为0.55 M。5例患者予以低剂量卡马西平治疗,均有效。PKD是一种罕见的神经系统发作性疾病,多种遗传学分析技术进行PRRT2基因检测有助于确诊。

Clinical manifestations and genetic diagnosis of paroxysmal kinesigenic dyskinesia

The clinical manifestations of five children with paroxysmal kinesigenic dyskinesia (PKD) were retrospectively analyzed and their gene mutations were analyzed by high-throughput sequencing and chromosome microarray. The 5 patients consisted of 4 males and 1 female and the age of onset was 6-9 years. Dyskinesia was induced by sudden turn movement, scare, mental stress, or other factors. These patients were conscious and had abnormal posture of unilateral or bilateral extremities, athetosis, facial muscle twitching, and abnormal body posture. The frequency of onset ranged from 3-5 times a month to 2-7 times a day, with a duration of <30 seconds every time. Electroencephalography showed no abnormality in these patients. Three patients had a family history of similar disease. The high-throughput sequencing results showed that a heterozygous mutation in the PRRT2 gene, c.649_650insC (p.R217PfsX8), was found in two patients; the mutation c.436C>T (p.P146S) was found in one patient; a splice site mutation, IVS2-1G>A, was found in one patient. The two mutations c.436C>T and IVS2-1G>A had not been reported previously. The chromosome microarray analysis was performed in one patient with negative results of gene detection, and the chromosome 16p11.2 deletion (0.55 Mb) was observed. Low-dose carbamazepine was effective for treatment of the 5 patients. PKD is a rare neurological disease. The detection of the PRRT2 gene by multiple genetic analysis can help the early diagnosis of PKD.