Pathogenic variants in DDX3X have recently been identified to be a relatively common cause of intellectual disability in females. In this study, we describe six female probands, from five unrelated families, with five novel heterozygous variants in DDX3X, and the identification of potential germline mosaicism. Consistent features between this cohort and previously described cases include developmental delay or intellectual disability, growth disturbance and movement disorder. Common facial dysmorphism within the cohort include short palpebral fissures, micrognathia, bulbous nasal tip, protruding ears, high arched palate, thin upper vermillion and smooth philtrum. Novel clinical features identified from this cohort include facial dysmorphisms, perinatal complications, valgus feet deformity, lipoatrophy, dystonic episodes, and cutaneous mastocytosis. This case series attempts to expand the phenotype of the DDX3X syndrome; however, it remains heterogeneous. Description of further cases is required to more accurately identify the significance of novel phenotypes within this cohort.

中文翻译：

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DDX3X综合征的表型扩展：6例新病例。

最近发现DDX3X中的致病变异是女性智力残疾的相对常见原因。在这项研究中，我们描述了来自五个不相关家庭的六个女性先证者，在DDX3X中具有五个新的杂合变异体，并鉴定了潜在的种系镶嵌。该队列与先前描述的病例之间的一致特征包括发育迟缓或智力残疾，生长障碍和运动障碍。队列中常见的面部畸形包括睑裂短，微棘突，鼻头球根扩张，耳朵突出，上颚弓高，上朱红薄和平滑的腓骨。从该队列中鉴定出的新临床特征包括面部畸形，围产期并发症，外翻足畸形，脂肪萎缩，肌张力异常发作和皮肤肥大细胞增多。该病例系列试图扩大DDX3X综合征的表型。但是，它仍然是异构的。需要更进一步的案例描述，才能更准确地识别该队列中新表型的重要性。