title: Facioscapulohumeral muscular dystrophy: Are telomeres the end of the story?
abstract: Facioscapulohumeral muscular dystrophy (FSHD) is a progressive myopathy with a relatively late age of onset (usually in the late teens) compared with Duchenne and many other muscular dystrophies. The current FSHD disease model postulates that contraction of the D4Z4 array at chromosome 4q35 leads to a more open chromatin conformation in that region and allows transcription of the DUX4 gene. DUX4 mRNA is stable only when transcribed from certain haplotypes that contain a polyadenylation signal. DUX4 protein is hypothesized to cause FSHD by mediating cytotoxicity and impairing skeletal muscle differentiation. We recently showed in a cell culture model that DUX4 expression is regulated by telomere length, suggesting that telomere shortening during aging may be partially responsible for the delayed onset and progressive nature of FSHD. We here put our data in the context of other recent findings arguing that progressive telomere shortening may play a critical role in FSHD but is not the whole story and that the current disease model needs additional refinement.
authors.affiliation: Department of Cell Biology; University of Texas Southwestern Medical Center; Dallas, TX USA.
authors.forename: Guido
authors.initials: G
authors.lastname: Stadler
authors.affiliation: Wellstone Program; Department of Cell & Developmental Biology; University of Massachusetts Medical School; Worcester, MA USA.
authors.forename: Oliver D
authors.initials: OD
authors.lastname: King
authors.affiliation: Department of Cell Biology; University of Texas Southwestern Medical Center; Dallas, TX USA.
authors.forename: Jerome D
authors.initials: JD
authors.lastname: Robin
authors.affiliation: Department of Cell Biology; University of Texas Southwestern Medical Center; Dallas, TX USA ; Center of Excellence in Genomic Medicine Research; King Abdulaziz University; Jeddah, Saudi Arabia.
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Shay
authors.affiliation: Department of Cell Biology; University of Texas Southwestern Medical Center; Dallas, TX USA.
authors.forename: Woodring E
authors.initials: WE
authors.lastname: Wright
keywords: Complex genetics; D4Z4 contractions; DUX4; compound heterozygotes; multifactorial