PCS/MVA syndrome caused by an Alu insertion in the BUB1B gene.

We report a case of premature chromatid separation/mosaic variegated aneuploidy syndrome identified by microcephaly on fetal ultrasound and confirmed by cytogenetic analysis of amniotic fluid. Initial mutational analysis of the entire coding region of the BUB1B gene failed to identify any causative mutations. However, further analysis revealed a known compound heterozygous mutation in the upstream region of this gene and a novel Alu insertion mutation in the intron.