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 is a complex genetic disorder that primarily affects the nervous system. Characteristic features of this condition include delayed development, intellectual disability, severe speech impairment, and problems with movement and balance (ataxia).n some people who have Angelman syndrome, the loss of a gene called OCA2 is associated with light-colored hair and fair skin. The OCA2 gene is located on the segment of chromosome 15 that is often deleted in people with this disorder.
The most common cause of Angelman syndrome is a deletion of the maternal chromosome region 15q11-q13, which includes the UBE3A gene. Importantly, mutations and deletions of the UBE3A gene are sufficient to cause Angelman syndrome, making UBE3A the single gene responsible for the core symptoms of the disorder. Two major deletion classes known as class I and class II deletions in the 15q11-q13 region both cause Angelman syndrome.