Splicing analyses of the ankyrin^Ankara mutation in reticulocyte RNA. (A) To determine if the ankyrin^Ankara mutation was associated with altered mRNA splicing, reticulocyte RNA was reverse transcribed with oligo d(T). RT products were PCR amplified with primers in exons 15 and 17. M indicates markers. Control (C) reticulocyte RT-PCR product yielded the expected cDNA fragment of 248 bp. In the father (F), the expected band of 248 bp and 3 additional bands of higher molecular weight were visualized. In the proband (P), the normal 248-bp cDNA product was not seen and only the 3 additional higher molecular weight bands visualized in the father's cDNA were found. (B) Determination of the nucleotide sequence of these higher molecular weight bands yielded novel ankyrin cDNA isoforms containing additional sequence of +15 bp, +172 bp, +257 bp and +260 bp, respectively, from the 3′ end of intron 16. The corresponding predicted splicing patterns of these isoforms are shown.