Edwards+Syndrome

Maggie Elliott Biology I Honors Ms. Beatty

Edward's Syndrome

Edward's Syndrome is a rare chromosomal syndrome in which the child has an extra third copy of chromosome #18. It is commonly referrred to as Trisomy 18 or Chromosomal Imbalance Syndrome. Edward's Syndrome is more severe than the common Down Syndrome. ES causes both mental retardation and physical effects that usually lead to the infant's death. Most parents choose to abort the baby before term, but if they make the decision to carry the baby until full term, there is a frequency of about 1-3,000. ES is seen more in girls than in boys, women over thirty are more likely to have a baby with this disorder.

__**Mode of Inheritance:**__ Edward's Syndrome is caused by a meiotic nondisjuction event. With nondisjunction, a gamete is produced with an extra copy of chromosome 18; the gamete then has 24 chromosomes. When combined with a normal gamete from the other parent, the embryo has 47 chromosomes, with three copies of chromosome 18. In some cases, Edward's Syndrome isn't inherited from the parents. More often than not, there is an error in the formation of egg and sperm that leads to ES. The error in cell division is known as nondisjunction, which results in a reproductive cell with an abnormal amount of chromosomes. __**Clinical Description of Edward's Syndrome:**__ Unfortunately, most babies die before birth. If the baby does happen to be born, almost all of their organs are affected. The baby will be mentally retarded, have high muscle tone, be prone to seizures, congenital heart defects. and brain defects. Physical signs include: a small head, small wide-set eyes, and a small lower jaw. The infan t will have severe bone growth retardation, clenched hands w ith 2nd and 5th fingers on top of the others, and other defects of the hands and feet. Also, malformations of the digestive tract, the urinary tract, and genitals.



__**Treatment:**__ There isn't a cure for this disorder, doctors are only able to treat the symptoms. Feeding specialists are needed to help the baby with their eating or feeding problem. Physical abnormalities can be treated with surgery or therapy. Although, extreme surgeries that would be needed may not be in the best interest of the infant whose life is more than likely measured in days. Most parents and doctors just choose to make the baby comfortable.

__**Detection:**__ You can screen for ES during pregnancy by measuring measuring the amount of free beta subunit of human chorionic gonadotropin in the blood of the pregnant mother. Other testing methods include: a diagnostic  procedure, amniocentesis and karyotyping. However, this diagnostic procedure involves risk to the woman and the baby. Amniocentesis and karyotyping are not routinely performed during all pregnancies. Instead, one or more screening methods may be utilized to determine when the risk to the pregnancy warrants the risk of undergoing an invasive diagnostic procedure.

Sources:

http://www.wrongdiagnosis.com/e/edwards_syndrome/intro.htm http://www.accessdna.com/condition/Trisomy_18/376 http://ghr.nlm.nih.gov/condition=trisomy18 http://rarediseases.about.com/cs/chromosome18/a/050104.htm http://en.wikipedia.org/wiki/Trisomy_18] http://www.answers.com/topic/edwards-syndrome-treatment\ http://www.patentstorm.us/patents/5100806/description.html