The 41-bp frameshift deletion (nucleotides 1709-1749) in the 5′ end of exon 11 protein 4.2 cDNA.

(A) Normal protein 4.2 cDNA sequence shown between nucleotides 1699-1779 (numbered according to Sung et al2). (B) The equivalent sequence in protein 4.2 Hammersmith, correctly spliced and containing the 1747G>T mutation (revealed by genomic DNA sequencing, as shown in Figure 4). The 1747G>T mutation introduces a Glu583→Stop substitution. (C) The equivalent misspliced sequence in protein 4.2 Hammersmith is shortened by the 41-bp frameshift deletion (bold and underlined characters in the control), which alters the reading frame and introduces a stop codon (TAG) as the ninth full codon of the frameshifted region following the deletion.