What Is Trisomy 18?

What Is Trisomy 18?

Trisomy 18, also known as Edwards syndrome, is a condition which is caused by a chromosomal defect. It occurs in about 1 out of every 3000 live births.

Unlike Down syndrome, which also is caused by a chromosomal defect, the developmental issues caused by Trisomy 18 are associated with medical complications that are more potentially life-threatening. 50% of babies who are carried to term will be stillborn, with baby boys having higher stillbirth rate than baby girls.

At birth, intensive care admissions in Neonatal units are most common for infants with Trisomy 18. Again, baby boys will experience higher mortality rates in this neonatal period than baby girls, although those with higher birth weights do better across all categories.


What causes Trisomy 18?

At conception, 23 chromosomes from the father and 23 chromosomes from the mother combine to create a baby with a set of 46 chromosomes in each cell. A trisomy occurs when a baby has three #18 chromosomes instead of the normal two. This is something that happens at conception. And although many parents worry about this, it is important to know that parents have done nothing before or during pregnancy to cause this disorder in their child.


There different types of Trisomy conditions. The most common trisomy is Trisomy 21, also known as Down syndrome, where a baby has three of the twenty-first chromosome.

Trisomy 18 is the second most common trisomy and occurs when a baby has three of the eighteenth chromosome. This results in 47 chromosomes instead of the normal 46 in the affected cells. It is this extra genetic material that causes the problems associated with Trisomy 18.

The third most common is Trisomy 13, also known as Patau syndrome.

Our baby girl has Full Trisomy 18:
The most common type of Trisomy 18 (occurring in about 95% of all cases) is full Trisomy. With full Trisomy, the extra chromosome occurs in every cell in the baby's body. This type of trisomy is not hereditary. It is not due to anything the parents did or did not do—either before or during pregnancy.


Typical characteristics of Trisomy 18 include:

Heart defects:
VSD (Ventricular Septal Defect): a hole between the lower chambers
ASD (Atrial Septal Defect): a hole between the upper chambers
Coarctation of the aorta: a narrowing of the exit vessel from the heart

Kidney problems
Part of the intestinal tract is outside the stomach (omphalocele)
The esophagus doesn’t connect to the stomach (esophageal artesia)
Excess amniotic fluid (polyhydramnios)
(Which I have had)

Clenched hands
Pocket of fluid on the brain (choroid plexus cysts)
Rocker bottom feet
Delayed growth
Small jaw (mycrognathia)
Small head (microcephaly)
Low-set ears
Strawberry-shaped head
Severe developmental delays
Umbilical or inguinal hernia 2 vessel umbilical cord


Give a Gift of Hope
http://www.trisomy18.org/site/PageServer?pagename=donate
Working together, your gift helps ensure that new families impacted by Trisomy 18 in 2010 will have the support they need and that more progress is made!

Your gift brings hope to families and their children coping with Trisomy 18 by investing in our efforts to fund research, build community and shape dialogue in the medical and research communities.


3 Ways to Give:

Trisomy 18 Foundation Mailing Address: OTHER WAYS TO DONATE:
Trisomy 18 Foundation Donate Online at www.trisomy18.org/donate
4491 Cheshire Station Plaza, Suite 157 or directly via the child's Legacy Page
Dale City, VA 22193 Phone: 810-867-4211 between 9 and 5 ET