Expansion of the phenotype of lateral meningocele syndrome

Lateral meningocele syndrome (LMS) is due to specific pathogenic variants in the last exon of NOTCH3 gene. Besides the lateral meningoceles, this condition presents with dysmorphic features, short stature, congenital heart defects, and feeding difficulties. Here, we report a girl with neurosensorial hearing loss, severe gastroesophageal reflux disease, congenital heart defects, multiple renal cysts, kyphosis and left-convex scoliosis, dysmorphic features, and mild developmental delay. Exome sequencing detected the previously unreported de novo loss-of-function variant in exon 33 of NOTCH3 p.(Lys2137fs). Following the identification of the gene defect, MRI of the brain and spine revealed temporal encephaloceles, inner ears anomalies, multiple spinal lateral meningoceles, and intra- and extra-dural arachnoid spinal cysts. This case illustrates the power of reverse phenotyping to establish clinical diagnosis and expands the spectrum of clinical manifestations related to LMS to include inner ear abnormalities and multi-cystic kidney disease.