TRACK Syndrome Caused by Homozygous TSEN2 c.1100-5T>A Variant Presenting with Atypical Hemolytic Uremic Syndrome and Early End-Stage Kidney Disease

Background: TRACK syndrome, first described by Canpolat et al., is a rare disorder caused by splice-site mutations in TSEN2, characterized by craniofacial malformations, central nervous system (CNS) anomalies, progressive kidney disease. Case Presentation: We present a 2.5-year-old boy, third child of consanguineous parents, admitted with fever and cough, diagnosed with atypical hemolytic uremic syndrome (aHUS). Whole exome sequencing revealed a homozygous intronic TSEN2 variant (c.1100-5T>A), consistent with TRACK syndrome. Two deceased siblings had similar dysmorphic features and early-onset renal failure. The proband exhibited microcephaly, craniofacial dysmorphism, left atrial dilation, and laboratory findings consistent with thrombotic microangiopathy (TMA). Despite pathogenic TSEN2 variant, he’d normal intellectual and motor development. He’s currently 6 years old, undergoing peritoneal dialysis, receiving biweekly eculizumab, and antiepileptic therapy. Conclusion: This report highlights a rare cause of aHUS and end-stage kidney disease (ESKD) due to a TSEN2 splice-site mutation, further expanding the phenotypic spectrum of TRACK syndrome.