Sequencing gels demonstrating the patients' DNA-mutation and the variant mRNA transcripts. (A) Sequencing of the patients' DNA shows a novel mutation, a heterozygous T → C transition at position +6 of intron C. (B) Sequencing of the RT-PCR product through exon 3/intron C boundary shows the incorporation of intronic sequence into the patients' mRNA and the T → C transition at position +6. * indicates altered amino acid sequence. (C) Sequencing of a truncated RT-PCR product in the antisense direction shows skipping of exon 3 (correct sequence in the boundary exons 2 and 3 is CAAG/AGTTT and exons 3 and 4 is ATTG/GTCGT.20 (D) Sequencing of a truncated RT-PCR-product shows skipping of exons 3 and 4 (correct sequence in the boundary of exons 4 and 5 is GAAG/ATGAG.20