Trisomy 18
Trisomy 18, more commonly known as Edwards syndrome, is a condition caused by an additional third chromosome attached to chromosome number 18 [1]. The additional chromosome creates an effect on the body that causes abnormalities and defects to the growth of organs in the fetus during pregnancy [2]. A person with Trisomy 18 often has slow growth before birth causing abnormalities such as heart defects, stomach, lungs and kidneys [3]. Other common symptoms after birth include a relatively low weight at birth [4], cleft palate, microcephaly (small head), micrognathia (small jaw) and deformed feet [5]. Trisomy 18 is caused by a nondisjunction in either the sperm or egg cell, meaning they have an extra chromosome and so is caused by random events during the fertilisation of the egg [6]. Trisomy 18 is not an inherited condition [7].
References
- ↑ Genetics Home Reference http://ghr.nlm.nih.gov/condition/trisomy-18#glossary
- ↑ Genetics Home Reference http://ghr.nlm.nih.gov/condition/trisomy-18#glossary
- ↑ What is Trisomy 18? http://www.webmd.com/baby/what-is-trisomy-18
- ↑ Genetics Home Reference http://ghr.nlm.nih.gov/condition/trisomy-18#glossary
- ↑ What is Trisomy 18? http://www.webmd.com/baby/what-is-trisomy-18
- ↑ What is trisomy 18? http://www.onhealth.com/trisomy_18/page2.htm#what_is_trisomy_18
- ↑ What is trisomy 18? http://www.onhealth.com/trisomy_18/page2.htm#what_is_trisomy_18