The Clinical Features of Facioscapulohumeral Muscular Dystrophy Associated With Borderline (>/=35 kb) 4q35 EcoRI Fragments.
OBJECTIVE
: The objectives of this study were to characterize the clinical features of facioscapulohumeral muscular dystrophy (FSHD) in patients with borderline (>/=35 kb) EcoRI fragments and to compare patients with borderline EcoRI fragments with FSHD patients harboring fragments of <35 kb.


BACKGROUND
: Most patients with FSHD harbor 4q35 EcoRI fragments of less than 35 kb. The clinical findings in patients with borderline fragments are not well known.


METHODS
: The authors conducted a retrospective review of patients with FSHD followed at a regional neuromuscular center over a 12-year period.


RESULTS
: Eleven patients with DNA-positive FSHD, found to harbor borderline (>/=35 kb) EcoRI fragments (group 1), were compared with 30 patients with fragments of <35 kb (group 2). Group 1 patients were less likely (18%) to present with the classic FSHD phenotype as compared with group 2 patients (63%). Statistically significant differences in clinical disease severity and manual muscle testing scores were noted between the 2 groups, with group 1 patients showing less severe weakness and disability at presentation.


CONCLUSIONS
: Patients with borderline fragments are more likely to have a partial or less severe form of FSHD, probably resulting from a less disruptive DNA alteration at the 4q35 locus.
Felice
Kevin J
KJ
From the Department of Neurology, University of Connecticut School of Medicine, Farmington, CT.
Whitaker
Charles H
CH