open chromosomes have a maternal pattern. Angelman syndrome is caused by a large deletion of the region of the maternal chromosome that contains UBE3A, or by a DNA sequence change (mutation ...

For instance, deletions that span a centromere result in an acentric chromosome that will most ... Also, the larger the deletion, the more genes are likely to be involved, and the more drastic ...

DiGeorge syndrome, a 22q11.2 deletion syndrome, is caused when a small portion of chromosome 22 is missing. The condition can occur in individuals born from a parent with the dominant contiguous ...