Primary Hypertrophic Osteoarthropathy: A case series

Skeletal dysplasia encompasses a spectrum of over 400 rare inheritable skeletal abnormalities typically manifested early in childhood. Hypertrophic Osteoarthropathy is a clinical syndrome marked by abnormal skin and osseous tissue proliferation at the distal extremities. It is characterized by unique clinical features such as digital clubbing, periostosis of tubular bones, and synovial effusions. We report three cases of HPOA for further understanding and insight into this infrequent cause of clubbing. Case 1 involved a 25-year-old male presenting with joint pain, primarily in wrists and knees, accompanied by progressive swelling in both lower limbs for the past 3 years. Case 2 featured a 31-year-old man born out of a second-degree consanguineous marriage, reporting pain in wrist, knee, and ankle joints bilaterally for 2 years, with a history of clubbing since birth. Case 3 featured a 19-year-old male with multiple joint pains and a family history. Genetic sequencing was performed for two cases, revealing mutations in the SLCO2A1 gene associated with impaired prostaglandin E2 (PGE2) degradation, leading to elevated PGE2 levels. While primary Hypertrophic Osteoarthropathy is an uncommon cause of clubbing, the diagnosis is often challenging. Genetic sequencing played a pivotal role in confirming the diagnosis in these cases, highlighting its importance in understanding and managing this condition. These case reports contribute to the limited literature on HPOA, particularly in the context of genetic testing, which is not routinely conducted in India