Ankylosing spondylitis complicating Turner syndrome: Two case reports and a literature review.

Rationale: Turner syndrome (TS) is an anomaly caused by loss of part of or all the X chromosomes. Ankylosing spondylitis (AS) is an HLA-B27-associated autoimmune disease with a male predominance. It is widely accepted that TS patients are at higher risk of autoimmune diseases, but AS in TS patients has only rarely been reported. Patient concerns: A 13-year-old TS patient presented with intermittent pain in both hip joints, and a 27-year-old TS patient presented with thoracic kyphosis and a history of AS. Diagnoses: Both patients were diagnosed with AS according to their symptoms, laboratory results, and imaging. Interventions: The first patient was treated with tocilizumab for 8 months, whereas the second patient was treated with diclofenac initially with subsequent surgery for thoracic kyphosis. Outcomes: Treatment relieved the symptoms of both patients and laboratory parameters improved. Lessons: Even though AS has a male predominance, clinicians should be aware that AS and TS may co-exist and that the clinical features are atypical in TS patients with AS.