X-linked centronuclear myopathy.

We report the cases of two male preterm newborns with X-linked centronuclear myopathy (CNM). This is the most severe type of CNM. Each of them presented with generalized hypotonia, weakness, difficulty in swallowing, and respiratory distress at birth. Physical examination of both newborns revealed long thin face, high-arched palate, mild bilateral ptosis, frog-leg posture, and absence of deep tendon reflex. Diagnosis of the disease was made according to fetal history, family history, muscle histopathology, electron microscopy, and genetic analysis. Subdural hemorrhage of brain and subcapsular hematoma of the liver were found at autopsy of Case 1. The results of molecular analysis of Case 2 and his family favored the diagnosis of X-linked CNM. Molecular studies can be easily performed with only minute amount of DNA of patients, and may help the clinician to predict which patients may be at the risk for medical complications.