What is Trisomy 18?
- Trisomy 18 occurs when a baby has 3 #18 chromosomes instead of the normal 2.
- Occurs in approximately 1 out of every 2500 pregnancies in the United States and about 1 in every 6000 live births.
- There are 3 types of Trisomy 18
- Full Trisomy 18 - The extra chromosome occurs in every cell of the body. This is the most common type of Trisomy 18 occurring in about 95% of all cases. This type is not hereditary.
- Partial Trisomy 18 - Only part of the extra chromosome is present. This type is very rare and may be caused by hereditary factors.
- Mosaic Trisomy 18 - The extra chromosome is present in some but not all of the cells of the body. This type is very rare and is not inherited.
- Trisomy 18 can be diagnosed before birth by performing and amniocentesis and through ultrasounds. If not diagnosed before birth the baby will have blood screenings done to get a definite diagnosis.
- Unlike Down Syndrome the developmental issues are associated with medical complications that are much more life threatening in the early months and years of life.
- 50% of babies carried to term will be stillborn. Boys have a higher stillbirth rate than girls
- Less than 10% of babies will survive to see their first birthday.
Characteristics/Birth Defects and Disorders associated with Trisomy 18
- Heart Defects
- Ventricular Septal Defect (VSD) - a hole between the lower chambers of the heart
- Atrial Septal Defect (ASD) - a hole between the upper chambers of the heart
- Coarctation of the aorta: a narrowing of the exit vessel from the heart.
- Kidney problems
- Clenched hands
- Pocket of fluid on the brain
- Rocker bottom feet
- Delayed growth
- Small jaw and small head
- Low set ears
- Sever developmental delays
- Umbilical hernia
- Cleft lip
- Feeding difficulties
- Gastroesophegeal reflux
- Slow post natal grow
- Kidney defects
- Urinary tract infections
Impact On The Family
- Denial and Isolation
- Individuals with Trisomy 18 will require medicine and different types of therapy.
- Doctors visits and hospital stays are not cheap.
- Funeral arrangements
Unfortunately most individuals do not live to see the inside of a classroom, however a few do and these students will need a lot of support to continue to grow and learn.
- Therapy should be provided (OT, PT, Speech)
- Different forms of assistive technology should be available (standers, wheelchairs, communication devices, etc.)
- Teachers and paras should be trained on how to meet the needs of the student (tracheostomy care, tube feeding, etc.)
Mieko's 1st Year-Trisomy 18 News Story
Mieko attended preschool where she received therapy and eventually learned how to walk with the assistance of a walker and crutches. She was a very happy little girl who loved to laugh and smile. However her life was sadly cut short at the age of 4 due to complications form Trisomy 18.
Carly's fifth birthday