FSHD-FOCUS: Facioscapulohumeral muscular dystrophy; (epi)genetic and environmental factors influencing disease severity

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant
inherited progressive muscular dystrophy, characterized by asymmetrical
weakness and wasting of facial, shoulder girdle and upper arm muscles, followed
by weakness of the muscles of the trunk and the lower extremities. Over the
last few years, our knowledge on the pathogenic mechanism in FSHD has expanded.
However, we have not yet explained the variability in onset, disease course and
penetrance, nor the asymmetric nature of the disease. Our hypothesis is, that
other (epi)genetic and environmental or lifestyle factors must be involved in
this disease. It is important to identify these factors, as some of them may be
considered as *natural moderators* of the disease and may contribute to
development of new treatment strategies. If such a treatment becomes available,
well controlled clinical trials will be warranted. Moreover, in the process of
unraveling the pathogenic mechanism of FSHD, new questions will arise. For the
purpose of future research, this study will provide a cohort of well-documented
FSHD patients. By establishing a disease specific biobank containing
biomaterial as well as clinical data of FSHD patients, future research will be
facilitated and accelerated.

The primary objective is to identify (epi)genetic and environmental disease
modifying factors that contribute to the variable clinical phenotype of FSHD,
in order to support the future development of new treatment strategies for
FSHD.
The secondary objectives are:
1. To describe the phenotype and genotype of Dutch FSHD patients in order to
obtain a well-documented cohort of FSHD-patients to be recruited for future
clinical trials.
2. To establish a disease oriented biobank for processing and storage of
biospecimen and health information of FSHD patients in order to facilitate
future research.

Explorative, cross-sectional, observational study.

Participants will visit the outpatient clinic at the department of neurology.
Their medical history will be taken, they will undergo a clinical examination
and they will fill out questionnaires online (at home). Blood samples will be
collected for DNA- and RNA-analysis and for storage of blood and DNA/RNA in a
biobank for future research. Also, participants will undergo a muscle biopsy of
the leg or a skin biopsy unless they object against this procedure. Another
visit will be planned for performing a magnetic resonance imaging (MRI) of
muscles of one upper leg. Complications of muscle or skin biopsies are very
uncommon and include hematoma and local hypoesthesia.