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.
Definition of Toxic and Poisonous. Toxic ââ refers to the condition of a substance and the degree to which it can cause damage to you or any other organism or system. In colloquial usage, toxic can refer to biological organisms and non-biological substances, the latter in a more allegorical context.