Clinical presentations that can sometimes be misleading in women who are carriers of FHL1-related myopathy

French clinicians have compiled clinical and genetic data from five female patients who were ultimately diagnosed as ‘carriers’ of myopathy linked to the FHL1 gene (located on the X chromosomeForme que prend l’ADN pendant la division cellulaire (aspect de fins bâtonnets). Il est composé de 2 bras, un bras long et un bras court. Par convention, le bras long s’appelle q, et le bras court s’appelle p. Chez l’être humain, il y a 23 paires de chromosomes (soit 46 chromosomes). Vingt-deux paires sont constituées de 2 chromosomes identiques, appelés autosomes. La vingt-troisième paire est constituée des chromosomes sexuels, XX chez la femme et XY chez l’homme.):

• the average age of onset of the first symptoms was 13 years,
• all patients had motor impairment, which was asymmetrical at the outset,
• in four of them, loss of the ability to walk was observed after an average of six years’ progression,
• the rapid rate of motor deterioration, combined with the pseudo-inflammatory appearance on imaging, had led to the mistaken suggestion of a myositis-like process,
• muscle biopsy ultimately revealed the presence of reducing bodies, raising suspicion of FHL1 gene involvement, which was subsequently confirmed by molecular biology.

The authors advocate investigating a hereditary cause in cases of atypical inflammatory myopathy.