Thin ribs in neonatal myotonic dystrophy.

The recently described thin ribs seen in a neonate suffering from myotonic dystrophy represents a valuable sign for early detection of this condition. Thin ribs were found on chest radiographs of two siblings a short time after birth. This led in retrospect to the diagnosis of neonatal myotonic dystrophy. The diagnosis was confirmed by clinical and electromyographic data of myotonic dystrophy in the mother who was not previously known to have the disease. Both children died at the age of 2 days from respiratory distress. All children of affected mothers should have a chest radiograph soon after birth in order to help in diagnosis and to establish the frequency of this sign.