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Washington University Experience | DEVELOPMENTAL MALFORMATIONS | Aqueductal Stenosis, Atresia & Septa | 12A0 Case 12 History
Case 12 History The patient was a 6-day-old preterm male, born at 33 week estimated gestational age from a G1P1 mother, with hydrocephalus due to severe aqueductal stenosis recognized antenatally by ultrasound. His mother denied exposure to illnesses or toxic substances during pregnancy. The mother did receive adequate prenatal care including ultrasounds, noninvasive prenatal testing, amniocentesis and chorionic villus sampling. The results of those tests were normal. MS-AFP showed low risk for an open neural tube defect. CVS was done at the11th week, and a CMA showed no genomic imbalances. Amniocentesis was done later; amniocytes were sent to GeneDx for L1CAM sequencing, which was negative. The patient was delivered by C-section with a birth weight of 2540 g (92%), length 47.5 (95%) and head circumference of 39.4 (>99%). Severe macrocephaly was noted, and a single umbilical artery was identified. The newborn received PPV, CPAP, was intubated and transferred to the NICU after being apneic. Head ultrasound on 9/20 showed severe hydrocephalus of the lateral (right greater than left) and 3rd ventricles. There was no subependymal, intraventricular, or intraparenchymal hemorrhage. There was thinning of the periventricular parenchyma. The corpus callosum is thin. He underwent a ventriculostomy with reservoir placement by neurosurgery and daily ventricular taps. An MRI examination performed on 9/25 revealed a 1) markedly enlarged lateral and third ventricles secondary to severe stenosis of the cerebral aqueduct. 2) Herniation of the right lateral ventricle into the posterior fossa resulting in a small cerebellum and kinking of the brainstem. 3) Severe dysgenesis of the corpus callosum and 4) Cervical cord syrinx. The child's condition continued to deteriorate, and a decision was made to remove the patient from life support. Chromosomal MicroArray was normal. Targeted next generation sequencing (Hydrocephalus Sequencing Panel with CNV Detection, Prevention Genetics) showed a variant of uncertain significance in AKT3 (c.752A>G, p.Tyr251Cys, heterozygous) with no other pathogenic mutations or copy number variation.
