Alternative splicing of FMRl gene in fetal and adult human brain

Fragile X syndrome can be caused by lack of expression of the FMRl gene, which encodes an RNA binding protein. Extensive alternative splicing of the FMRl gene has been observed in human and mice. Five regions of the FMRl gene have been reported to be alternatively spliced. To determine whether such alternative splicing might be developmentally regulated, RT-PCR was used to analyze poly(A) RNA transcripts of the FMRl gene in adult and fetal human brain. A new alternative acceptor site in exon 17 that may lead to a truncation of the last 53 ammo acids of the FMRl protein was described. This acceptor site was used in several regions of fetal brain but not in adult cortex. The results suggest that alternative splicing of the FMRl gene may be subject to developmental switching