Recurrent Lower Limb Venous Thrombosis in a Young Adult with Myotonia Congenita.

A 20-year-old male with myotonia congenita presented with recurrent episodes of lower limb deep vein thrombosis. Initial genetic testing confirmed a homozygous mutation in the CLCN1 gene. Although rare, a possible link between congenital myotonia and venous thromboembolism (VTE) is explored in this case. Triple-positive antiphospholipid antibodies confirmed a diagnosis of thrombotic antiphospholipid syndrome, necessitating indefinite anticoagulation. Literature review highlights RNA toxicity, mis-splicing, and coagulation activation in myotonic disorders. This is the first known case correlating congenital myotonia with recurrent VTE. Early suspicion and genetic testing are crucial for timely intervention and improved outcomes.