A refined diagnostic algorithm for Bethlem myopathy

Abstract

Immunofluorescent labeling of collagen VI in fibroblast cultures is a useful addition to current diagnostic services for Bethlem myopathy (BM). It can be used to guide molecular genetic testing, the gold standard diagnostic technique for BM, in a cost-effective and time-saving manner.

Diagnosis and management of the limb girdle muscular dystrophies

“…A very similar pattern of contractures, without primary cardiac involvement, can be seen in Bethlem myopathy due to mutations in the collagen VI genes 21 22. Here the pattern of muscle weakness is more typically proximal than the humeroperoneal involvement seen in the various types of Emery–Dreifuss muscular dystrophy.…”

Bethlem myopathy: long-term follow-up identifies COL6 mutations predicting severe clinical evolution

“…COLVI immunolabelling of skin fibroblasts from 20 index patients and controls was carried out, as previously reported, using either the protocols described by Demir et al 3 or by Hicks et al 24. Slides were observed with an Axioplan 2 microscope (Zeiss) equipped with a HBO 100 mercury lamp (Zeiss).…”

The collagen VI-related myopathies

“…In the milder BM, this lack of connection between collagen VI and the basement membrane may only be partial and sometimes may not be apparent at all (Pan et al, 2003), thus the muscle immunohistochemical analysis can appear to be normal. Analysis of collagen VI production in dermal fibroblast cultures can also be helpful in implicating collagen VI as being involved, ranging from completely absent or severely reduced with intracellular retention in UCMD to more subtle abnormalities in BM (Jimenez-Mallebrera et al, 2006; Hicks et al, 2008). …”