Involvement of the larynx in a congenital "myopathy", unilateral aplasia of the arytenoid, micrognathia, and malformation of the brain--a new syndrome?

Neuromyopathic changes were found in various limb muscles and in intrinsic laryngeal muscles of a two month old girl. She had been noted to have micrognathia, arthrogryposis and congenital stridor and died as a result of respiratory insufficiency and aspiration. Autopsy revealed an absent left arytenoid cartilage and severe histogenic abnormalities of the brain. Although the muscles involved showed a mainly myopathic pattern, marked signs of peripheral neurogenic involvement were present. These differed from motor neuron disease or aplasia of anterior horn cells. These findings cast a new light on the discussion of unclassified congenital myopathy resembling the picture of congenital muscular "dystrophy". This is the first case of congenital neuromyopathy in which involvement of intrinsic laryngeal muscles has been demonstrated morphologically.