Multicolor fluorescence in situ hybridization on metaphase chromosomes and interphase Halo-preparations using cosmid and YAC clones for the simultaneous high resolution mapping of deletions in the dystrophin gene

We report on multicolor fluorescence in situ hybridization
protocols for the simultaneous visualization of deletion-prone
regions for carrier detection of Duchenne/ Becker (DMD/BMD)
muscular dystrophy. Cosmid and yeast artificial chromosome (YAC)
clones specific for preferentially deleted subregions of the
dystrophin gene were labeled differentially and detected with three
different fluorochromes using digital imaging microscopy. This
approach allows for an assessment of the carrier status of female
relatives even in families where no index patient is available.
Cosmid and YAC clones, and different probe-generation protocols are
compared with respect to their feasibility for carrier detection.
The use of histone-depleted interphase nuclei (Halo-preparations)
for deletion mapping is demonstrated and shown to have a resolution
power of 5 kb.