RESUMO
Objective To develop an operational gene diagnosis method for Chinese Facioscapulohumeral muscular dystrophy (FSHD) patients Methods Genomic DNAwas double digested with restriction enzymes EcoRⅠ/HindⅢ and EcoRI/BlnI,respectively The digested fragments were separated on a 0 6% agarose gel After transferred to a Nytran SuperCharge Membrane, the fragmented DNAs were hybridized with the probe p13E 11 The hybridizing fragments were analyzed by the software ImageMaster Total Lab v1 11 and the size of each band was then given Results Only a 4q35 EcoRI+HindIII/P13E 11 fragment larger than 33 kb was detected in each of the controls Two fragments were detected in each of the 33 FSHD patients, one of which was smaller than 33 kb Although there was also presence of two small alleles in the 3 other FSHD cases, either of them turned out to be 10q26 derived owing to its BlnI sensitivity Interestingly, we found a sporadic patient who carried three 4q35 type fragments and, strikingly, two of them were smaller than 33 kb In the analysis of FSHD family members, a 9 year old boy with no clinical signs was found to share the small fragment with his affected father, indicating that he may be a pre symptomatic patient Conclusion The double digestion associated Southern blotting method we developed can be applied to both the diagnosis of FSHD patients and the prediction of pre symptomatic patients Furthermore, by the gene detection using this method, we first got the evidence of translocation between 4q and 10q in Chinese FSHD patients, which may be helpful to the elucidation of the pathogenesis of FSHD