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.
Down Syndrome. Down syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is typically associated with physical growth delays, characteristic facial features, and mild to moderate intellectual disability.PubMed Health Glossary.(Source: Wikipedia).own syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is typically associated with physical growth delays, characteristic facial features, and mild to moderate intellectual disability. PubMed Health Glossary. (Source: Wikipedia).