ABSTRACT Facioscapulohumeral Muscular Dystrophy is a common form of muscular
dystrophy that presents clinically with progressive weakness of the facial, scapular, and
humeral muscles, with later involvement of the trunk and lower extremities. While typically
inherited as autosomal dominant, facioscapulohumeral muscular dystrophy (FSHD) has a
complex genetic and epigenetic etiology that has only recently been well described. The
most prevalent form of the disease, FSHD1, is associated with the contraction of the D4Z4 …

Abstract Purpose of Review: This article describes the clinical characteristics, diagnosis,
molecular pathogenesis, and treatment of facioscapulohumeral muscular dystrophy (FSHD).
Recent Findings: FSHD comprises two genetically distinct types that converge on a common
downstream pathway of the expression of the toxic protein DUX4. Approximately 95% of
patients have FSHD type 1 (FSHD1), in which loss of DNA repetitive elements (D4Z4
repeats) in the subtelomeric region of chromosome 4q causes decreased methylation and …

Facioscapulohumeral muscular dystrophy (FSHD) is characterized by a typical and
asymmetric pattern of muscle involvement and disease progression. Two forms of FSHD,
FSHD1 and FSHD2, have been identified displaying identical clinical phenotype but
different genetic and epigenetic basis. Autosomal dominant FSHD1 (95% of patients) is
characterized by chromatin relaxation induced by pathogenic contraction of a macrosatellite
repeat called D4Z4 located on the 4q subtelomere (FSHD1 patients harbor 1 to 10 D4Z4 …