我们描述了两名在13号染色体长臂中末端缺失的无关患者,显示由全前脑和小脑疣发育不全组成的脑畸形。阵列比较基因组杂交分析显示,一名患者的13q31.3q34纯末端缺失,另一名患者的镶嵌环染色体具有13q32.2q34缺失。位于13q32区域内的ZIC2中的突变导致全前脑畸形,而13q32.2q32.3区域与小脑蠕虫发育不全(Dandy-Walker综合征)相关。在我们的患者中,这些主要脑畸形的罕见并发提供了进一步的证据,即13q32.2q32.3缺失,携带ZIC2和ZIC5,导致小脑发育不全。
We describe two unrelated patients with terminal deletions in the long arm of chromosome 13 showing brain malformation consisting of holoprosencephaly and cerebellar vermis hypoplasia. Array comparative genomic hybridization analysis revealed a pure terminal deletion of 13q31.3q34 in one patient and a mosaic ring chromosome with 13q32.2q34 deletion in the other. Mutations in ZIC2, located within region 13q32, cause holoprosencephaly, whereas the 13q32.2q32.3 region is associated with cerebellar vermis hypoplasia (Dandy-Walker syndrome). The rare concurrence of these major brain malformations in our patients provides further evidence that 13q32.2q32.3 deletion, harboring ZIC2 and ZIC5, leads to cerebellar dysgenesis.