Essay Archive - Myotonic Dystrophy
Myotonic Dystrophy
Myotonic dystrophy is an dominant disorder characterized by
myotonia, muscular dystrophy, cataracts, hypogonadism, frontal balding, and
EKG changes. The discovery that the genetic defect is an amplified
trinucleotide repeat in the 3-prime untranslated region of a protein kinase
gene on chromosome 19 explains many of the unusual features of this
disorder. Problems can range from very mild to very severe even within the
same family, and it is not always obvious who in the family has the gene
alteration. Severity varies with the number of repeats: normal individuals
have from 5 to 30 repeat copies; mildly affected persons, from 50....
|