A simplified approach for FSHD molecular testing.

Background: Facioscapulohumeral muscular dystrophy (FSHD) is characterized by complex genetics linked to DNA rearrangements in a polymorphic genomic region of tandemly repeated D4Z4 segments. A panel of FSHD biomarkers including contracted D4Z4 array repeat combined with the 4qA(159/161/168)PAS haplotype has been proposed as molecular signature for defining alleles causally related to FSHD. The aim of the present study was to develop a simple approach for FSHD molecular testing in order to extend studies related to the applicability of FSHD molecular signature in Greek population.

Methods And Results: The method comprises: (i) visual genotyping of the common 4qA and 10qA subtelomeric haplotypes by a multiplex assay in a dipstick format. (ii) Detection of 4qA161 haplotype in D4Z4 contracted alleles by tri-primer PCR. (iii) Detection of PAS SNP in PLAM region and G>C SNP in the first proximal D4Z4 unit by tri-primer PCR. The method was evaluated by analysing DNA from monoallelic sources representing common 4q and 10q haplotypes, samples from 3 FSHD families, 36 unrelated probands and 38 control individuals of Greek origin.

Conclusions: The proposed method could be a very useful tool for FSHD testing making it more accessible to clinical diagnostic laboratories and the wider FSHD community.