Nakashima Mitsuko, Takano Kyoko, Tsuyusaki Yu, Yoshitomi Shinsaku, Shimono Masayuki, Aoki Yoshihiro, Kato Mitsuhiro, Aida Noriko, Mizuguchi Takeshi, Miyatake Satoko, Miyake Noriko, Osaka Hitoshi, Saitsu Hirotomo, Matsumoto Naomichi
Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
J Hum Genet. 2016 Jul;61(7):653-61. doi: 10.1038/jhg.2016.27. Epub 2016 Mar 31.
West syndrome is an early-onset epileptic encephalopathy characterized by clustered spasms with hypsarrhythmia seen on electroencephalogram (EEG). West syndrome is genetically heterogeneous, and its genetic causes have not been fully elucidated. WD Repeat Domain 45 (WDR45) resides on Xp11.23, and encodes a member of the WD repeat protein interacting with phosphoinositides (WIPI) family, which is crucial in the macroautophagy pathway. De novo mutations in WDR45 cause beta-propeller protein-associated neurodegeneration characterized by iron accumulation in the basal ganglia. In this study, we performed whole exome sequencing of individuals with West syndrome and identified three WDR45 mutations in three independent males (patients 1, 2 and 3). Two novel mutations occurred de novo (patients 1 and 2) and the remaining mutation detected in a male patient (patient 3) and his affected sister was inherited from the mother, harboring the somatic mutation. The three male patients showed early-onset intractable seizures, profound intellectual disability and developmental delay. Their brain magnetic resonance imaging scans showed cerebral atrophy. We found no evidence of somatic mosaicism in the three male patients. Our findings indicate that hemizygous WDR45 mutations in males lead to severe epileptic encephalopathy.
韦斯特综合征是一种早发性癫痫性脑病,其特征为脑电图(EEG)显示的成串痉挛伴高峰节律紊乱。韦斯特综合征具有遗传异质性,其遗传病因尚未完全阐明。WD重复结构域45(WDR45)位于Xp11.23,编码与磷酸肌醇相互作用的WD重复蛋白(WIPI)家族成员,该家族在巨自噬途径中起关键作用。WDR45的新发突变导致β-螺旋桨蛋白相关神经变性,其特征为基底神经节中铁蓄积。在本研究中,我们对韦斯特综合征患者进行了全外显子组测序,并在三名独立男性(患者1、2和3)中鉴定出三个WDR45突变。两个新发突变(患者1和2),另一个在男性患者(患者3)及其患病姐姐中检测到的突变是从母亲遗传而来的,母亲携带体细胞突变。这三名男性患者均表现为早发性难治性癫痫发作、严重智力残疾和发育迟缓。他们的脑磁共振成像扫描显示脑萎缩。我们在这三名男性患者中未发现体细胞镶嵌现象的证据。我们的研究结果表明,男性半合子WDR45突变会导致严重的癫痫性脑病。