The Italian consortium dedicated to facioscapulohumeral muscular dystrophy (FSHD) reports on its experience in integrating methylation studies into the routine diagnosis of this myopathy with an excessively complex pathophysiology:
- 218 patients with or suspected of having FSHD were included in the study,
- in addition to measuring the number of D4Z4 repeats and 4qA/B haplotyping, methylation was specifically studied in two critical areas of the D4Z4 locus, namely DUX4-PAS and DR1,
- the sensitivity and specificity of the test were found to be very acceptable,
- the test enabled confirmation of the diagnosis of FSHD (FSHD1 or FSHD2), even in pre- or pauci-symptomatic individuals.
This work once again highlights the importance of epigenetic factors in FSHD.