Down syndrome is a genetic condition where a child is born with an extra copy of the 21st chromosome. Although genetic testing is available to provide detection during birth, for many moms, like Dr. Nicole Stoecken from MercyOne Grimes Pediatric Care Clinic, a surprise diagnosis at birth is also possible.
Since Dr. Stoecken gave birth to her fourth child, Josie, who was born with Down syndrome in Dec. 2019, she has become an advocate and guide for children with a diagnosis of Down syndrome. As a pediatric physician, Dr. Stoecken works with new moms daily. She provided some frequently asked questions she’s received from new parents of children with Down syndrome.
What is Down syndrome and how common is the diagnosis?
Human cells contain 23 pairs of chromosomes. In each pair, you receive one chromosome from each parent. Down syndrome is the result of abnormal cell division within chromosome 21. The person with the disorder isn’t suffering, Down syndrome is simply a part of what they are, not who they are. There is nothing ‘down’ about Down syndrome. The name actually derives from the physician, John Langdon Down, who was first to recognized and describe the genetic condition in 1862.
The extra genetic material in the 21st chromosome is responsible for the characteristic features and developmental delays of Down syndrome, which can present as one of three genetic variations:
Trisomy 21. In around 95 percent of cases, Down syndrome is caused by abnormal cell division during the development of the sperm or egg cell, resulting in the person having three copies of chromosome 21, instead of the usual two copies in all cells.
Translocation Down Syndrome. Children with Translocation Down Syndrome have the usual two copies of chromosome 21, but before or at conception, additional genetic material from chromosome 21 attaches to another chromosome.
Mosaic Down Syndrome. In this rare variation of Down syndrome, the extra copy of chromosome 21 is only present in some cells, resulting in a mosaic of normal and abnormal cells caused by abnormal cell division after fertilization.
Annually, Down syndrome is present in 6,000 births, or 1 in 700 babies, making it the most common genetic disorder in the United States.
What tests are available during pregnancy to detect a genetic disorder and when does a diagnosis usually take place?
During pregnancy, there are screening test options for detecting a genetic disorder, which are safe for mother and baby, and pose no risk of possible miscarriage. However, they aren’t able to detect with certainty if a fetus is affected. Diagnostic tests are offered to parents if their screening test reports a possible abnormality. These tests are extremely accurate at detecting abnormalities, but do pose a small, less than one percent risk of miscarriage:
Sequential Integrated Screening Test. These tests are taken in two steps. The first takes place within the first trimester of pregnancy. A maternal blood sample is taken and a nuchal translucency ultrasound measures the amount of fluid in the back of the baby’s neck. The process is repeated at 15-20 weeks as the second step. If there is an excess of fluid discovered in the ultrasound, an abnormality may be present.
Amniocentesis. Chromosomal problems, such as Down syndrome, are commonly identified with an amniocenteses. These genetic testing procedures are typically performed between 15 and 20 weeks of pregnancy. With the guidance of an ultrasound, a small amount of amniotic fluid is removed by a needle inserted through the abdomen. The cells from the fluid are cultured and an analysis of the chromosomal make-up of the cells, a karyotype analysis, is performed.
Chorionic Villus Sampling (CVS). A CVS diagnostic test is able to be performed earlier then an amniocentesis, usually at 10 to 12 weeks of pregnancy. Like the amniocentesis, a CVS is most commonly used to identify chromosomal abnormalities, such as the type seen in Down syndrome. With ultrasound guidance a catheter is inserted through the cervix or a needle is inserted through the abdomen to retrieve a tiny piece of tissue from the placenta. The tissue is then cultured and a karyotype analysis of the chromosomal make-up of the cell is performed.
What are some of the unique, physical features present in children with Down syndrome?
With Down syndrome, there can be common, distinct features present. Yet, even these physicality’s are variable and individuals with Down syndrome will still look like the members of their family. Some common, physical features may include:
- Almond-shaped eyes (palpebral fissures)
- Tiny, white spots around the iris of the eyes (Brushfield spots)
- Flattened facial profile
- Small ears
- Shortened or widened neck
- Prominent or protruding tongue
- Small hands with a single crease in the palm
- Shortened stature
What medical conditions should parents be aware of?
There is a vast array of medical conditions that can be present in children with Down syndrome. Just as the physical features, each person is an individual and their medical conditions vary from person to person.
Muscle Hypotonia. Issues affecting the muscle afflict almost all individuals with Down syndrome and contribute to most of their medical diagnoses, and can contribute to common growth and fine motor delays encountered early in life. Although people with this genetic disorder can be very strong, muscle hyptonia is the inability to relax the muscles. The individual retains a certain amount of tension and stiffness which can be felt as resistance to movement.
Heart Defects. A congenital heart defect is present in around 50 percent of children born with Down syndrome. In some cases, a heart problem will require surgery in early infancy.
Hearing Loss. Due to their anatomy, people with Down syndrome may have issues with their middle-ear fluid causing repeated ear infections, which can have an impact on their hearing.
Vision Problems. Common eye diseases and refractory errors can lead to a person needing glasses.
Leukemia. Children with Down syndrome have an increased risk of leukemia.
Sleep Apnea. Due to their soft tissue and a unique skeletal structure around the neck, it is common for the airway to be obstructed, especially in a rested state.
This is only a short list of possible medical conditions potentially present in an individual with Down syndrome. Each person is different and I encourage you to keep in constant communication with a regular physician as they’re the best resource for knowing their patient and being able to monitor for potential problems along the way.
Dr. Nicole Stoecken is accepting new patients at the MercyOne Grimes Pediatrics Care Clinic. If you’d like to schedule a pediatric appointment you can contact her by calling the clinic at 515-300-3900. To find a provider in your area, visit mercyone.org/find-a-location/.
About the Author
Dr. Nicole Stoecken received her undergraduate degree in Integrative Physiology from The University of Iowa before attending medical school at Des Moines University. She served her residency at Blank Children’s Hospital in Des Moines where she was chief resident her third year.
She has been a General Pediatrician at MercyOne Pediatric Clinics for the past 5.5 years. She started at MercyOne West Pediatrics Clinic where she worked for 2.5 years before transitioning to the new MercyOne Grimes Pediatric Clinic in January 2018.
Dr. Stoecken lives in Grimes with her husband Andy and 4 children, Emma, Blake, Brooks, and Josie. She enjoys activities outdoors with her family including boating at the lake, hiking, and playing in the backyard. She is passionate about advocating for all children’s health as well as the inclusion of all individuals in our schools, communities, and society. She lives by the motto, “be a kind human” always!
This article is part of a series of sponsored articles by MercyOne Des Moines Medical Center