Best Answer: Chordata refers to the presence of a nerve chord running from the head to the back, which may or may not be accompanied by vertebrae. All animals with backbones are members of the chordate phylum, but not all chordates have bones (lancelets and tunicates are chordates lacking real bones).
Angelman syndrome (AS) is a genetic disorder that causes developmental delay, intellectual disability, speech problems, seizures (epilepsy), and problems with movement and balance (ataxia).ngelman syndrome (AS) is a severe neurodevelopmental disorder caused by maternal deficiency of the imprinted gene UBE3A. Individuals with AS suffer from intellectual disability, speech impairment, and motor dysfunction. Currently there is no cure for the disease.
Improper imprinting can result in an individual having two active copies or two inactive copies. This can lead to severe developmental abnormalities, cancer, and other problems. Prader-Willi and Angelman syndrome are two very different disorders, but they are both linked to the same imprinted region of chromosome 15. Some of the genes in this region are silenced in the egg, and at least one gene is silenced in the sperm.