What is trisomy 18?
Trisomy 18 is a condition caused by an extra copy of chromosome 18. Chromosomes provide the genetic instructions that program the body to form, grow and develop. Having an extra copy of chromosome 18 causes the body to form differently.
What are the challenges with trisomy 18?
The most common differences seen in individuals with trisomy 18 are poor growth, heart anomalies, brain anomalies, eye anomalies, cleft lip, cleft palate, kidney anomalies and problems with the digestive system. In addition to physical differences, the body also works differently. Breathing problems, feeding difficulties and developmental disabilities are common. Most babies with trisomy 18 are not able to overcome the challenges and pass away in the first few weeks or months of life.
What causes trisomy 18?
Trisomy 18 is caused by and extra chromosome 18 being present in either the egg or sperm that made the baby. This condition occurs sporadically, meaning parents cannot cause it to happen. Trisomy 18 does not typically run in families. Occasionally, one parent may have a chromosome rearrangement that increases the chance of having children with chromosome differences. It is important that a chromosome analysis be completed to ensure accurate recurrence risk information is shared with the family.
How common is trisomy 18?
Trisomy 18 is seen in approximately 1 in 5,000 live-born infants.