M – 100bp DNA marker (New England Biolabs); Lane 1 variant carrier; Lanes 2–5, normal unaffected female controls; lane 6, no-template control. Controls revealed only expected product sizes of 654bp for full length transcript, and 406bp for common exon 3 deletion isoform previously reported in healthy controls. The variant carrier in Lane 1 shows an aberrant product of 548bp, that was confirmed by sequencing to be an exon 2 deletion. The loss of exon 2 includes the position of the ATG start site, complicating prediction of the molecular consequences of this aberration.