Intracranial hemorrhage secondary to vitamin K deficiency in X-linked myotubular myopathy.

X-linked myotubular myopathy (XLMTM) is a rare congenital myopathy characterized by profound hypotonia and poor respiratory effort at birth. The condition is associated with multiple morbidities including chronic respiratory insufficiency, feeding tube dependence, and rarely, vitamin K deficiency leading to bleeding and coagulopathy. We report a case of a 6-month-old boy with X-linked myotubular myopathy who experienced a fatal intracranial hemorrhage due to vitamin K deficiency without prior clinical evidence of cholestasis or micronutrient deficiency. We propose clinically non-apparent cholestasis in combination with acute illness and poor weight gain led to his vitamin K deficiency and intracranial hemorrhage. However, the etiology and mechanism of his cholestasis remains unclear. We conclude that children with X-linked myotubular myopathy, especially with gene therapy on the horizon, may benefit from routine hepatic, coagulation, and nutritional screening to prevent potentially catastrophic bleeding.