What is the definition or description of: edwards syndrome?

Trisomy 18: Edwards Syndrome happens with a frequency 1 in 6000 live births, and is the 2nd most common chromosomal syndrome, where there is an extra copy or part of an extra 18th chromosome. The classic physical findings include prominent occiput, clenched hands, and usually significant structural heart defects. The life span is short with usually severe mental retardation, and many medical issues...

Edwards Syndrome: Trisomy 18 occurs in about 1/5,000 live births. It is a chromosomal condition due to random events that occur while egg or sperm are forming & isn't usually inherited. 5 to 10% live beyond 12 months. Jaw, mouth & head are small, ears are low-set, sternum is short / May have heart defects, low birth weight, seizures, scoliosis, spina bifida, high BP, cleft palate & lip, hearing loss & intellectual