Facioscapulohumeral muscular dystrophy

genotype-phenotype relationships

It is well established that the residual repeat size is related to the severity and age at onset of the disease. Other parameters influencing the severity are somatic mosaicism (i.e. the percentage of affected cells) and the gender. Except for the latter, these parameters do not explain the intrafamilial variability.

By studying large Dutch FSHD families, we are currently refining the genotype – phenotype relationships. Only families with at least 10 affected family members are included in this survey. Affected and non-affected family members are clinically evaluated by an expert neurologist and the complete allele constitution on chromosomes 4 and 10 is established by pulsed field gel electrophoresis (More information: Silvère van der Maarel, PhD. E-mail: maarel@lumc.nl or George W. Padberg, MD PhD. E-mail: g.padberg@czzoneu.azn.nl).