Chronic hepatitis with myopathy
Author:
Pediatric Oncall
Question
A 1½ years old boy had fever with elevated liver enzyme sin January 2009. He continued to have persistently elevated liver enzymes and was referred in May 2009 for further management. There was no jaundice. On examination, he had no significant abnormality and no organomegaly. His Hepatitis A IgM, HBsAg, Hepatitis E ELISA and Hepatitis C antibody were negative. His ANA, anti smooth muscle antibody, anti LKM were negative. Serum alpha fetoprotein and urine aminoacidogram were normal. Liver biopsy copper content was 11.3 µg, gm though 24 hrs urine copper was 132.3. He continued to have elevated liver enzymes and at 4½ years of age, he presented with difficulty to get up from sitting position. On examination, he had calf hypertrophy with Gower’s sign positive. His CPK was 15,560 IU, L and EMG showed primary myopathy.
Is it Duchene muscular dystrophy or is it glycogen storage disease_?
Expert Opinion :
There are 11 glycogen diseases {GSD}, nine of which are associated with myopathy. Most of these glycogen storage myopathies are associated with dynamic symptoms and signs in that the major neuromuscular complaints are exercise-induced muscle pain, cramps, and myoglobinura {e.g., GSD V or McArdle`s disease associated with myophosphorylase deficiency}. The other types of glycogen storage myopathies are considered static in that they are associated with fixed weakness rather than dynamic symptoms and signs. The static glycogen storage myopathies include: GSD I or Pompe`s disease {acid maltase or {-glucosidase deficiency}, GSD II or Cori-Forbes disease {debranching enzyme deficiency}, and GSD IV or Andersen`s disease {branching enzyme deficiency}.
Since this child does not have organomegaly, the static myopathy of GSD seems to be ruled out. The manifestation is not dynamic and thus predominantly myopathic GSD is also unlikely.
In this child, he was proven to have DMD by FISH