title: A case of hereditary inclusion body myopathy: 1 patient, 2 novel mutations.
abstract: Hereditary inclusion body myopathy is an autosomal recessive disorder that presents in early adulthood with slowly progressive weakness sparing the quadriceps. Muscle histopathology reveals rimmed vacuoles without inflammation. The disorder is caused by a mutation in the gene for UDP-N-acetylglucosamine 2-epimerase-N-acetylmannosamine kinase (GNE), a bifunctional enzyme involved in protein glycosylation. Over 40 mutations have been described to date. We present a case of a young woman with progressive lower extremity weakness. Clinical presentation, laboratory evaluation, electrodiagnostic testing, muscle pathology, and genetic sequencing are described. The patient was found to have heterozygous mutations in the GNE gene, confirming the diagnosis of hereditary inclusion body myopathy. The mutations she carried have not been described previously. We briefly review the clinical, histopathologic, and molecular genetic findings of this disorder.
authors.affiliation: Departments of *Neurology daggerPathology, Penn State Hershey Medical Center, Hershey, PA double daggerThe HIBM Research Group, Encino, CA.
authors.forename: Justin
authors.initials: J
authors.lastname: Fisher
authors.forename: Javad
authors.initials: J
authors.lastname: Towfighi
authors.forename: Daniel
authors.initials: D
authors.lastname: Darvish
authors.forename: Zachary
authors.initials: Z
authors.lastname: Simmons