摘要分析1例神经发育障碍伴步态异常、言语缺失和皮质白质减少（NDAGSW，OMIM#617807）患儿的临床表型及分子遗传学特征。患儿为1岁9个月男性，体格发育迟缓，外观畸形包括眼眶周围饱满、眼裂上斜、人中短、帐篷嘴和锥形指；全面发育迟缓伴语言障碍、肌张力低下和步态异常。头颅磁共振成像、视觉诱发电位检查结果示非特异性改变。全外显子测序检出患儿 RAB11B基因新发杂合突变c.202G>A（p.Ala68Thr），为已报道的NDAGSW致病性热点变异。NDAGSW的临床表现为严重的智力障碍、失语、运动迟缓、步态异常伴特殊表观特征，脑部结构异常，头颅影像学检查可见脑白质减少、小脑发育不全、胼胝体发育不良。根据疾病特点得出 RAB11B基因c.202G>A（p.Ala68Thr）杂合错义突变是本例患儿的遗传学病因。

abstractsThe purpose of this investigation was to elucidate the clinical characteristics and genetic underpinnings of a pediatric patient with neurodevelopmental disorder with ataxic gait, absent speech, and decreased cortical white matter (NDAGSW, OMIM#617807). The affected individual, a 1-year-9-month-old male, displayed physical development retardation and distinctive facial features, notably periorbital puffiness, upward-gazing palpebral fissures, a shortened philtrum, a tented mouth, and conical-shaped digits. Clinically, the patient presented with profound global developmental retardation, marked language deficits, hypotonia, and an ataxic gait. Subtle, non-diagnostic alterations were identified in cranial magnetic resonance imaging and visual evoked potential assessments. The trio-whole exome sequencing analysis revealed a de novo heterozygous mutation, c.202G>A (p.A68T), within the RAB11B gene, a known pathogenic variant linked to NDAGSW. Neurodevelopmental disorders due to RAB11B gene variants are rare disorders with clinical manifestations of severe mental retardation, aphasia, motor retardation, gait abnormalities with peculiar phenotypical features, structural abnormalities of the brain, and reduced cerebral white matter, cerebellar hypoplasia, and hypoplasia of the corpus callosum as seen on cranial imaging. Based on the characteristics of the disease, the heterozygous missense mutation c.202G>A (p.Ala68Thr) in the RAB11B gene was identified as the genetic etiology of the child.