A Rare Case of Pediatric X-Linked Hypophosphatemic Rickets: Challenges and Insights from Pakistan

Author(s): Raamish Aamir Khan*, Zaib U Nisa Tariq, Maryum Akhter, Ifra Sultan Khan, Imtiaz Hussain

Introduction and Importance: X-linked hypophosphatemic rickets (XLHR) is a rare hereditary disorder characterized by impaired phosphate metabolism, leading to skeletal deformities and growth retardation. XLHR prevalence rates vary globally, with limited data from Pakistan. This case report presents a 14-month-old boy from Pakistan with XLHR, detailing the clinical presentation, diagnostic approach, and management.

Case Presentation: The individual displayed common symptoms of XLHR, such as stunted growth, limb abnormalities, and biochemical irregularities. Radiographic assessments confirmed skeletal alterations typical of XLHR. Treatment involved phosphate supplementation alone, as active vitamin D analogs were avoided due to prior vitamin D injections resulting in intoxication. Close monitoring and follow-up were implemented.

Clinical Discussion: This case highlights the clinical features and management of XLHR in a Pakistani pediatric patient. Early recognition with radiographic imaging is crucial to identify distinct skeletal abnormalities and biochemical tests showing elevated alkaline phosphatase (ALP) and renal phosphate wasting. Molecular genetic testing confirms the diagnosis by detecting PHEX mutations. Management typically includes oral phosphate supplements and active vitamin D analogues varying on the case to counteract excess fibroblast growth factor 23 (FGF23) and Burosumab, a novel therapy targeting FGF23. Despite optimal medical management, some patients may require surgical correction for worsening skeletal deformities, with methods ranging from growth modulation techniques to more invasive procedures like osteotomies and fixation.

Conclusion: This case highlights the challenges of recognising and reporting rare genetic disorders like X-linked hypophosphatemic rickets (XLHR) in Pakistan due to limited data and awareness. Improved access to genetic testing and increased awareness among healthcare professionals is crucial for better management and support for affected individuals and families, ultimately improving outcomes and quality of life.