Figure 7. CRYBB2 mutation in family JPM1. A: Sequence analysis of CRYBB2 genomic DNA indicates heterozygosity in the proband’s father (II.7) at cDNA pos. 177 (red arrow). B: Comparison of the wild-type sequence (Z99916) with the proband’s father sequence demonstrates that the G→C exchange at cDNA-position 177 leads to an exchange of Trp by Cys (W59C). The BseY1 restriction site in the wild-type sequence is underlined. C: Restriction analysis using the enzyme BseYI leads to an additional fragment of 137 bp in the mutant DNA (red); it demonstrates the presence of the mutation in the affected father (II.7) and the affected brother (III.1) of the proband (III.2). The asterisks mark the additional band of 137 bp indicating the mutation; “undig” is an undigested PCR fragment of 239 bp. WT represents an independent control from the laboratory; M=marker.