A rare chromosomal anomaly with clinical manifestations of mild to severe intellectual deficit, severe developmental delay, hypotonia with tendency to develop progressive hypertonia over time, minor facial anomalies and agenesis of the corpus callosum. Thirty to fifty percent of individuals have autism. An inverted duplication with a terminal deletion of the short arm of chromosome 8 mostly occurs as either an inverted duplication from centromere to D8S552 with a pter deletion from D8S349 or as an inverted duplication from 8p11.2 or 8p21 to D8S552, with a telomeric deletion from D8349. The input of the 8p deletion to the clinical picture appears less significant than the 8p inversion duplication rearrangement. To date, all invdupdel(8p) have occurred de novo. [from
SNOMEDCT_US]