ABSTRACT
My laboratory originally identified D4Z4 as part of a screening strategy designed to identify novel homeobox genes. A chromosome 4-specific cosmid library was probed with a degenerate oligonucleotide for homeobox sequences. Detailed mapping and partial sequencing of one of the positive clones (cosmid 13E) showed it to contain a tandem array of DNA repeats, initially defined by a 3.3 kb KpnI fragment and subsequently designated D4Z4 (Wijmenga et al., 1992; van Deutekom et al., 1993; Hewitt et al., 1994). This whole region of chromosome 4q35 has subsequently been found to be packed with low and high copy repeats. Thus, the identification of the p13E-11 probe from cosmid 13E by Cisca Wijmenga in 1992 represented a tour de force in cloning. This probe was pivotal in identifying the causative mutation in FSHD (Wijmenga et al., 1992) and is now invaluable for molecular diagnostics.
