A 36 years old woman in her first pregnancy was referred at 24w3d for a dedicated neurosonographic examination due to a suspected short corpus callosum (CC). The examination depicted a dysgenetic CC with asymmetric thickness at the level of the body in coronal views, very thin in the midline and thicker in both sides, suggesting bilateral formation of Probst bundles. The BPD, HC, and transverse cerebellar diameters were in the normal low range without associated growth restriction. Associated anomalies were not detected in the brain or other organs. Following genetic consultation and a normal CMA, trio exome sequencing was performed and a de novo missense pathogenic mutation c.2353 C > T in the DHX30 gene was detected. This variant has been previously reported in children and adults, mostly with a severe phenotype including neurodevelopmental disorder with variable motor and language impairment, but also mild phenotypes have been reported. MRI describes delayed myelination, ventriculomegaly, and cortical and cerebellar atrophy as imaging features in affected patients. This is the first prenatal report of a DHX30-associated neurodevelopmental disorder in which the fetus presents with isolated callosal dysgenesis, stressing the importance of exome sequencing in fetuses with this condition, as far as it is phenotypic presentation of numerous syndromes with different outcomes.

中文翻译：

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孤立性胼胝体发育不全胎儿 DHX30 基因的新发致病性变异

一名 36 岁的女性第一次怀孕，因怀疑胼胝体短 (CC)，于 24 周 3 天转诊进行专门的神经超声检查。检查显示，在冠状面视图中，身体水平的发育不良CC具有不对称的厚度，中线非常薄，两侧较厚，表明双侧形成了普罗布斯特束。BPD、HC 和小脑横径均处于正常较低范围，无相关生长限制。在大脑或其他器官中没有检测到相关异常。在进行遗传咨询和正常 CMA 后，进行了三重外显子组测序，并检测到DHX30基因中的从头错义致病性突变 c.2353 C > T。这种变异以前曾在儿童和成人中报道过，大多具有严重的表型，包括神经发育障碍，伴有不同程度的运动和语言障碍，但也有轻度表型的报道。MRI 将髓鞘形成延迟、脑室扩大以及皮质和小脑萎缩描述为受影响患者的影像学特征。这是第一份关于DHX30相关神经发育障碍的产前报告，其中胎儿出现孤立性胼胝体发育不全，强调了外显子组测序对患有这种情况的胎儿的重要性，因为它是具有不同结果的多种综合征的表型表现。