Prader-Willi syndrome is caused by a missing gene on chromosome 15. Normally, parents each pass down a copy of this chromosome. The defect can occur in a couple of ways: The father's genes are missing on chromosome 15; There are defects or problems with the fatherâs genes on chromosome 15
poison meaning, definition, what is poison: a substance that can make people or animals ill or kill them if they eat or drink it: . Learn more.
Top definition. a pill. a person who is can just get on every nerve, they are bitter and basically hard to swallow like a pill. omg that girl is such a pill, i could kill her! #bitter#annoying#mad#dick#bitch. by willhavehalloweenonchristmas December 18, 2013.