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Adult-Onset Presentation of Glutaric Acidemia Type II With Myopathy

Michael C Mareska1, Kristin K Adams, Joseph Muenzer

  • 1From the Departments of *Neurology and daggerPediatrics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and the double daggerDepartment of Pediatrics, the University of Colorado School of Medicine, Denver, Colorado.

Journal of Clinical Neuromuscular Disease
|December 17, 2008
PubMed

Insights

Glutaric acidemia type II (GA II), a rare metabolic disorder, can present solely as myopathy in adults. Early diagnosis and treatment with riboflavin and carnitine can improve symptoms.

Area of Science:

  • Biochemistry
  • Genetics
  • Neurology

Background:

  • Glutaric acidemia type II (GA II) is a rare metabolic disorder.
  • Typically presents in newborns with metabolic acidosis, hypoglycemia, and dysmorphic features.
  • Adult-onset GA II is uncommon, with only 11 cases previously reported.

Purpose of the Study:

  • To report a unique case of adult-onset GA II presenting solely as myopathy.
  • To highlight the importance of considering metabolic disorders in the differential diagnosis of late-onset weakness.

Main Methods:

  • A 23-year-old pregnant woman presented with progressive weakness and was diagnosed with lipid myopathy.
  • Metabolic studies and urine organic acid analysis suggested multiple acyl-CoA dehydrogenase deficiency.
  • Skin fibroblast immunoblotting confirmed a deficiency in electron transfer flavoprotein-ubiquinone oxidoreductase.

Main Results:

  • The patient exhibited significant muscle weakness, diagnosed as lipid myopathy.
  • Metabolic investigations pointed towards a deficiency in multiple acyl-CoA dehydrogenases.
  • Treatment with carnitine, riboflavin, and dietary modifications led to improved muscle strength and reduced urine organic acids.

Conclusions:

  • This case demonstrates that Glutaric acidemia type II can manifest exclusively as myopathy in adults.
  • Metabolic disorders should be considered in the differential diagnosis of unexplained adult-onset weakness.
Abstract

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