Facioscapulohumeral muscular dystrophy molecular testing using a non radioactive protocol

Although the facioscapulohumeral muscular dystrophy (FSHD) locus was mapped to 4q35 chromosomal region in 1990, no gene transcript has been as yet identified. Molecular diagnosis is based mainly on the detection of deletions of a 3.3 kb-tandem repeat array in the locus. This procedure offers almost 95% accuracy but is quite complicated and therefore a simpler test would be preferable. We describe a convenient non-radioactive protocol which requires a simple PCR probe synthesis and labelling procedure, thus facilitating and accelerating the standard Southern blot based DNA test. 134 individuals (113 affected and 21 unaffected relatives) were studied and a causal deletion was detected in 72.