Trisomy 18, also known as Edwards syndrome, is a rare genetic disorder resulting from an extra copy of chromosome 18. It is associated with severe congenital malformations, distinct clinical features, and high morbidity and mortality. Despite the odds, we describe the case of a 16-year-old female patient with trisomy 18. During a well-child visit with her pediatrician, the patient's parents express concerns about worsening seizure activity. Her seizures began at the age of nine and were initially well managed with anti-epileptics but eventually progressed to refractory generalized and myoclonic epilepsy, resulting in the placement of a vagus nerve stimulator (VNS) at the age of 13. Though this intervention initially extended seizure-free periods, they have gradually increased in frequency and duration since its placement. Additional past medical and surgical history is pertinent for Dandy-Walker malformation, omphalocele repair, corrected bowel malrotation, gastrostomy tube dependence, genitourinary malformations with recurrent urinary tract infections (UTIs), a bicuspid aortic valve, and surgical correction of three congenital heart defects: an atrial septal defect (ASD), a ventricular septal defect (VSD), and patent ductus arteriosus (PDA). Little is known about factors associated with long-term survival in patients with trisomy 18, emphasizing the importance of cases like ours that highlight the evolving clinical course, the importance of trisomy 18-specific growth curves, complex medical and surgical management, and efforts to support and encourage caregivers as these patients age.

Keywords: congenital heart defects; edwards syndrome; genetics; intractable seizures; karyotype; perinatal; trisomy 18.

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