Fetal Presentation of Walker–Warburg Syndrome With a Novel POMT1 Splice‐Altering Variant: Antenatal Imaging, Postmortem MRI , Autopsy, and Molecular Correlation

Walker–Warburg syndrome (WWS) is a fatal autosomal recessive disorder characterized by brain and eye malformations, and prenatal diagnosis relies heavily on neuroimaging findings to guide targeted genetic screening. Here, we describe a distinctive second‐trimester fetal imaging pattern observed in two siblings. In vivo and postmortem fetal magnetic resonance imaging demonstrated hydrocephalus, fused ventricles, hypoplastic cerebellar hemispheres, a small supraoccipital meningoencephalocele, and a recurrent hypoplastic ‘Z’‐shaped brainstem configuration. Whole‐exome sequencing identified a homozygous deletion in POMT1 (c.123‐11_123‐5del), confirmed by Sanger sequencing, and RNA sequencing suggested reduced expression of exon 3. Recognition of a ‘Z’‐shaped brainstem on fetal MRI should raise strong suspicion for WWS associated with POMT1 mutations, prompting integrated pathological assessment and genetic testing, particularly when there is a positive family history.