A Rare Tetrad of Sickle Cell Disease, Vascular Ehlers-Danlos Syndrome, Primary Ciliary Dyskinesia, and Phelan-McDermid Syndrome in a Saudi Child: A Complex Multisystem Pediatric Case Report.

Background: The coexistence of sickle cell disease (SCD), vascular Ehlers-Danlos syndrome (vEDS), primary ciliary dyskinesia (PCD), and Phelan-McDermid syndrome (PMS) in a single pediatric patient is extremely rare and poses substantial diagnostic and management challenges.

Case presentation: We report an 8-year-old male from Jazan, Saudi Arabia, born to consanguineous parents, with early-onset SCD, followed by the identification of vEDS, PCD, and PMS through clinical presentation and whole exome sequencing. His disease course has been exceptionally severe, marked by monthly hospitalizations, multiple PICU admissions, and a wide spectrum of systemic complications.

Conclusions: The coexistence of SCD, vEDS, PCD, and PMS may lead to synergistic vascular, pulmonary, and neurodevelopmental compromise, demanding multidisciplinary long-term management. This case underscores the need for a comprehensive targeted genetic assessment in patients with unusually aggressive or syndromic SCD phenotypes, particularly in regions with high levels of consanguineous marriages.