A partial deletion of the short arm of chromosome 8 with manifestations of low birth weight, postnatal growth deficiency, mild intellectual deficit, hyperactivity, craniofacial abnormalities, and congenital heart defects. The prevalence is unknown but 8p23.1 deletions are rare. The clinical manifestations are variable and do not depend on the size of the deletion, since this is the same in the majority of patients. Most 8p23.1 deletions occur de novo, however, parents can carry and transmit the chromosomal rearrangement to their children as well, with a risk of 50% for each child. [from SNOMEDCT_US]