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

French clinicians have compiled the clinical and genetic data of 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 at which the first symptoms appeared 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 rapidity of motor deterioration, combined with the pseudo-inflammatory appearance on imaging, had led to the mistaken suggestion of a myositis-related 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.