Limb-girdle muscular dystrophy type 2I is not rare in Taiwan

Neuromuscul Disord. 2013 Aug;23(8):675-81. doi: 10.1016/j.nmd.2013.05.010. Epub 2013 Jun 22.

Abstract

Alpha-dystroglycanopathy is caused by the glycosylation defects of α-dystroglycan (α-DG). The clinical spectrum ranges from severe congenital muscular dystrophy (CMD) to later-onset limb girdle muscular dystrophy (LGMD). Among all α-dystroglycanopathies, LGMD type 2I caused by FKRP mutations is most commonly seen in Europe but appears to be rare in Asia. We screened uncategorized 40 LGMD and 10 CMD patients by immunohistochemistry for α-DG and found 7 with reduced α-DG immunostaining. Immunoblotting with laminin overlay assay confirmed the impaired glycosylation of α-DG. Among them, five LGMD patients harbored FKRP mutations leading to the diagnosis of LGMD2I. One common mutation, c.948delC, was identified and cardiomyopathy was found to be very common in our cohort. Muscle images showed severe involvement of gluteal muscles and posterior compartment at both thigh and calf levels, which is helpful for the differential diagnosis. Due to the higher frequency of LGMD2I with cardiomyopathy in our series, the early introduction of mutation analysis of FKRP in undiagnosed Taiwanese LGMD patients is highly recommended.

Keywords: Alpha-dystroglycan; Alpha-dystroglycanopathy; Dilated cardiomyopathy; FKRP; Glycosylation defect; Laminin binding; Limb-girdle muscular dystrophy type 2I; Muscle imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cardiomyopathies / etiology
  • Cardiomyopathies / genetics
  • Child
  • Cohort Studies
  • DNA Mutational Analysis
  • Dystroglycans / metabolism*
  • Female
  • Gene Expression Regulation / genetics
  • Humans
  • Male
  • Muscle, Skeletal / diagnostic imaging
  • Muscle, Skeletal / pathology
  • Muscular Dystrophies, Limb-Girdle / diagnosis
  • Muscular Dystrophies, Limb-Girdle / epidemiology*
  • Muscular Dystrophies, Limb-Girdle / metabolism
  • Pentosyltransferases
  • Proteins / genetics
  • Radiography
  • Retrospective Studies
  • Taiwan / epidemiology
  • Tomography Scanners, X-Ray Computed
  • Young Adult

Substances

  • Proteins
  • Dystroglycans
  • FKRP protein, human
  • Pentosyltransferases

Supplementary concepts

  • Muscular Dystrophy, Limb-Girdle, Type 2I