Thymidine Kinase 2 Deficiency-Induced Adult-Onset Ptosis and Proximal Weakness.

Abstract

Thymidine kinase 2 (TK2) deficiency is an extremely rare disease with a variable onset age and symptoms.1, 2 Proximal muscle weakness, respiratory failure, facial weakness, and ptosis are the main symptoms. Deoxycytidine (dC) and deoxythymidine (dT) supplements might be a potential treatment after a timely diagnosis.3 Here, we report a patient with adult-onset ptosis and proximal muscle weakness who was finally diagnosed as having TK2-related myopathy.