Fig. 4.

Results on RNA level. a Expression analysis of TCOF1 in peripheral blood RNA from the patient (M18662). The integrity of the RNA samples was demonstrated by amplification of an RNA-specific fragment of the ACTB locus. The upper TCOF1 product was derived from the wild-type allele (WT), while the lower product was derived from the allele harboring the deletion of exon 3 (del). +RT = RT-PCR with reverse transcriptase, –RT = RT-PCR without reverse transcriptase, H₂O = RT-PCR without RNA. b Sequencing of the breakpoint on RNA level and scheme of TCOF1. The result of the sequencing of the patient's transcripts with the forward (F_Ex1) and reverse (R_Ex4) primer is shown. The schemes above depict the WT mRNA of TCOF1 and the transcript lacking exon 3. The breakpoint is indicated by a dashed line. The thus introduced premature stop codon is indicated by an asterisk in exon 5 together with the truncation. The results confirm that exon 2 is spliced directly onto exon 4. Black and grey squares = exons, small grey squares = UTR, horizontal dashed line indicates that not all exons are shown.