Rearrangement of the ELN gene. (A) 3′ RACE PCR was performed using a PAX5-specific primer and an anchor primer. We obtained a 1000-bp product that corresponds after sequencing to a part of PAX5 fused to the ELN transcript from its exon 2. (B) FISH analysis with the ELN BAC probe (CTD-2278A11). (C) Amplification of the 2 alternative transcripts by RT-PCR: PAX5a-ELN and PAX5b-ELN from the mRNA of patient 1.