A Case of Congenital Myotonic Dystrophy Diagnosed by Molecular Genetics

ABSTRACT

Congenital myotonic dystrophy is a progressive degenerative disease of the neuromuscular system, usually inherited in an autosomal dominant fashion. Affected infant presents with varying degrees of respiratory failure, often necessitating immediate and prolonged ventilatory assistance. An expression of a CTG (cystosine-thymine-guanine) repeat in the 3'-unsaturated region of a protein kinase gene contributes to the development of myotonic dystrophy. We experienced a case of congenital myotonic dystrophy in a male neonate with respiratory difficulty, hypotonia and difficulty in sucking and swallowing. His mother had mild manifestations of adult type myotonic dystrophy. PCR analysis revealed that CTG repeats in the myotonic dystrophy gene of the neonate and the mother were about 800 and 100 respectively.